The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the ...The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the integrated engineering technology of post-fracturing drilling,coring and monitoring of shale and the analysis of fracture source tracing,the evaluation of the fracture network after fracturing in the three-dimensional development of shale gas was conducted.The data of core fractures after fracturing indicate that three major types of fractures are formed after fracturing:natural fractures,hydraulic fractures,and fractures induced by external mechanical force,which are further classified into six subcategories:natural structural fractures,natural bedding fractures,hydraulic fractures,hydraulically activated fractures,drilling induced fractures,and fractures induced by core transportation.The forms of the artificial fracture network after fracturing are complex.Hydraulic fractures and hydraulically activated fractures interweave with each other,presenting eight forms of artificial fracture networks,among which the“一”-shaped fracture is the most common,accounting for approximately 70%of the total fractures.When the distance to the fractured wellbore is less than 35 m,the density of the artificial fracture network is relatively high;when it is 35–100 m,the density is lower;and when it is beyond 100 m,the density gradually increases.The results of the fracture tracing in the core sampling area confirm that the current fracturing technology can essentially achieve the differential transformation of the reservoir in the main area of Jiaoshiba block in Fuling.The three-layer three-dimensional development model can efficiently utilize shale gas reserves,although there is still room for improvement in the complexity and propagation uniformity of fractures.It is necessary to further optimize technologies such as close-cutting combined with temporary blocking and deflection within fractures or at fracture mouths,as well as limited flow perforation techniques,to promote the balanced initiation and extension of fractures.展开更多
Due to severe mass transfer limitations,contaminated soils with low-permeability limit the accessibility of amendments,resulting in less effective or even ineffective remediation.Enhancing the mass transfer properties...Due to severe mass transfer limitations,contaminated soils with low-permeability limit the accessibility of amendments,resulting in less effective or even ineffective remediation.Enhancing the mass transfer properties of low-permeability soils by hydraulic fracturing is a promising technique.A quasi-three-dimensional(quasi-3D)analytical model was presented that accounted for advection-diffusion-adsorption-degradation processes in the fracture-matrix system.The model combined the injection-extraction technique to investigate the enhanced transport of amendments in low-permeability contaminated soil by hydraulic fractures.Then,the injection strategy and controllable parameter optimization were comprehensively studied by analyzing the radial transport behavior of the amendment within hydraulic fractures.The results showed that higher injection volumetric rates accelerated the formation of a uniform line source within the fractures.Although the differences in the effective ratio of the amendment among different injection modes were not significant,considering the amendment utilization rate and cost reduction,the recommended injection strategy was the combination of continuous pulsing injection and periodic injection.展开更多
Low temperature and low permeability are the challenges for the development of hydrate reservoirs in permafrost.The ice produced around the production well caused by high depressurization driving force reduces the gas...Low temperature and low permeability are the challenges for the development of hydrate reservoirs in permafrost.The ice produced around the production well caused by high depressurization driving force reduces the gas production,and it is necessary to reduce the effect of ice production on gas production.In this work,a new combination of fracturing technology and depressurization method was proposed to evaluate the gas production potential at the site DK-2 in Qinghai-Tibet Plateau Permafrost.A relatively higher intrinsic permeability of the fracture zone surround the horizontal production well was created by the fracturing technology.The simulation results showed that the fracture zone reduced the blocking of production ice to production wells and promoted the propagation of production pressure.And the gas production increased by 2.1 times as the radius of the fracture zone increased from 0 to 4 m in 30 years.Nearly half of the hydrate reservoirs were dissociated in 30 years,and greater than 51.7%of the gas production was produced during the first 10 years.Moreover,production behaviours were sensitive to the depressurization driving force but not to the thermal conductivity.The growth of gas production was not obvious with the intrinsic permeability of the fracture zone higher than 100 m D.The effect of ice production on gas production by fracturing technology and depressurization method was limited.展开更多
Hydraulic fracturing technology is an important means of shale gas development,and microseismic monitoring is the key technology of fracturing effect evaluation.In this study,hydraulic fracturing and microseismic moni...Hydraulic fracturing technology is an important means of shale gas development,and microseismic monitoring is the key technology of fracturing effect evaluation.In this study,hydraulic fracturing and microseismic monitoring were simultaneously conducted in the Eyangye 2HF well(hereinafter referred to as EYY2HF well).The target stratum of this well is the second member of the Doushantuo Formation of the Sinian System,which is the oldest stratum of horizontal shale gas wells in the world.A total of 4341 microseismic fracturing events were identified,and 23 fracturing stages of the well were defined.The fluctuation of the number of events showed a repeating“high-low”pattern,and the average energy of these events showed minimal differences.These findings indicate that the water pressure required for the reconstruction of the EYY2HF well is appropriate.The main body of the fracture network extended from northwest to southeast,consistent with the interpretation of regional geological and seismic data.The stimulated rock volumes showed a linear increase with the increase of the fracturing stage.Some technological measures,such as quick lift displacement,quick lift sand ratio,and pump stop for secondary sand addition,were adopted during fracturing to increase the complexity of the fracture network.Microseismic fracture monitoring of the well achieved expected eff ects and guided real-time fracturing operations and fracturing eff ect evaluation.展开更多
The reservoir depthi ranges from 2300 m to 3950 m.It is of 14 sand formations that consist of 28 layers,of which 24 layers have a thickness of 5-20 m.Mainly composed of feldspar.quartz silt and fine sandstones.the res...The reservoir depthi ranges from 2300 m to 3950 m.It is of 14 sand formations that consist of 28 layers,of which 24 layers have a thickness of 5-20 m.Mainly composed of feldspar.quartz silt and fine sandstones.the reservoir is affected by com-paction,leading to poor physical properties.Core analysis indicates that the S:interval has a porosity of 17.4%.an air permeability of 50X 10 pμm’,a shale content of 7.2%.carbonate content of 5.3%,and median grain diameter of 0.19 mm.展开更多
Limited by serious heterogeneity both horizontally and vertically, water driving of low-permeability layers in Qiaokou oilfield appears to be very difficult. As the classⅠ layer reaches the stage of high water-conten...Limited by serious heterogeneity both horizontally and vertically, water driving of low-permeability layers in Qiaokou oilfield appears to be very difficult. As the classⅠ layer reaches the stage of high water-content too early, the level of exploitation became worse with low-recovery. Regarding the serious heterogeneity and low recovery in layers class Ⅱand Ⅲ, composite fracturing technology suitable for this kind of reservoir was applied. Its basement was a lab study of indoor water driving efficiency and fracturing experiment. Perfect result has achieved by using the technology.展开更多
Shale gas is a kind of environmentally friendly energy difference between the conventional natural gas, shale gas in shale interlayer containing mineral machine quality, most distributed in the basin topography, shale...Shale gas is a kind of environmentally friendly energy difference between the conventional natural gas, shale gas in shale interlayer containing mineral machine quality, most distributed in the basin topography, shale interlayer thickness is bigger, is because between rock and rock cracks and voids, save for a long time, biological decomposition, degradation. There is also a very small amount of shale gas dissolved in asphaltenes and kerogen. Domestic shale gas resources are very rich, and its utilization can reduce the emission of other polluting gases, but there are certain risks in the exploitation of shale gas. For this, this paper makes a detailed study on the pressure technology and the performance of fracturing oil for the exploitation of shale gas at home and abroad, and analyzes in detail the characteristics, application methods and application scope of various fracturing technologies, which also briefly describes the current development status of shale gas.展开更多
This paper discusses the digital application and benefit analysis of building information model(BIM)technology in the large-scale comprehensive development project of the Guangxi headquarters base.The project covers a...This paper discusses the digital application and benefit analysis of building information model(BIM)technology in the large-scale comprehensive development project of the Guangxi headquarters base.The project covers a total area of 92,100 square meters,with a total construction area of 379,700 square meters,including a variety of architectural forms.Through three-dimensional modeling and simulation analysis,BIM technology significantly enhances the design quality and efficiency,shortens the design cycle by about 20%,and promotes the collaboration and integration of project management,improving the management efficiency by about 25%.During the construction phase,the collision detection and four-dimensional visual management functions of BIM technology have improved construction efficiency by about 15%and saved the cost by about 10%.In addition,BIM technology has promoted green building and sustainable development,achieved the dual improvement of technical and economic indicators and social and economic benefits,set an example for enterprises in digital transformation,and opened up new market businesses.展开更多
There are abundant tight sandstone gas resources in the Sichuan Basin,which are the important objects of reserve and production increase and large-scale development.Due to their discontinuous sandbody distribution,nar...There are abundant tight sandstone gas resources in the Sichuan Basin,which are the important objects of reserve and production increase and large-scale development.Due to their discontinuous sandbody distribution,narrow channels,and strong horizontal and vertical heteroge-neity,however,conventional fracturing technologies cannot achieve the ideal stimulation effect here.In order to address this difficulty,this paper dissects the geology engineering characteristics of tight sandstone gas reservoirs in the western Sichuan Basin.Starting from the seepage mechanics theory,the concept of“multi-scale high-density”tight gas fracturing technology is put forward by fully referring to the experience of previous multi-round reservoir stimulation in the western Sichuan Basin and the idea of unconventional volume fracturing technology.In addition,its conceptual connotation,key technologies and implementation effects are illustrated.The following research results are obtained.First,the seepage characteristics make it necessary for the efficient production of tight gas reserves to increase fracture density and stimulated reservoir volume(SRV).Second,the“multi-scale high-density”fracturing technology emphasizes the rationality of high-density hydraulic fracture creation and the matching of multi-scale fractureflow capacity,and aims at establishing a multi-level fracture system with effective and steady gasflow in tight reservoirs through fracturing.Third,the“wide,dense,support,stable,and precise”fracturing technology is applied to improve single well production and estimated ultimate recovery(EUR).Fourth,the engineering practice of“multi-scale high-density”fracturing technology in the tight reservoirs of Jurassic Shaximiao Formation and Triassic Xujiahe Formation in the ZJ Gas Field realizes the average single well production rate of 15.6104 m3/d,which is 1.96 times higher than that before the stimulation.Obviously,it provides powerful support for the operation of the ZJ Gas Field into a giant gasfield with the reserves of 100 billion cubic meters.In conclusion,the formation of the concept and key technologies of“multi-scale high-density”fracturing technology effectively supports the efficient development of tight gas in the western Sichuan Basin and points out the following research direction of tight gas reservoir stimulation.The research results provide reference and guidance for the large-scale benefit development of tight gas in China.展开更多
Grid-level large-scale electrical energy storage(GLEES) is an essential approach for balancing the supply–demand of electricity generation, distribution, and usage. Compared with conventional energy storage methods, ...Grid-level large-scale electrical energy storage(GLEES) is an essential approach for balancing the supply–demand of electricity generation, distribution, and usage. Compared with conventional energy storage methods, battery technologies are desirable energy storage devices for GLEES due to their easy modularization, rapid response, flexible installation, and short construction cycles. In general, battery energy storage technologies are expected to meet the requirements of GLEES such as peak shaving and load leveling, voltage and frequency regulation, and emergency response, which are highlighted in this perspective. Furthermore, several types of battery technologies, including lead–acid, nickel–cadmium, nickel–metal hydride, sodium–sulfur, lithium-ion, and flow batteries, are discussed in detail for the application of GLEES. Moreover, some possible developing directions to facilitate efforts in this area are presented to establish a perspective on battery technology, provide a road map for guiding future studies, and promote the commercial application of batteries for GLEES.展开更多
In the present paper, continuum fracture mechanics is used to analyze the Smart-Cut process, a recently established ion cut technology which enables highly efficient fabrication of various silicon-on-insulator （SOI）...In the present paper, continuum fracture mechanics is used to analyze the Smart-Cut process, a recently established ion cut technology which enables highly efficient fabrication of various silicon-on-insulator （SOI） wafers of high uniformity in thickness. Using integral transform and Cauchy singular integral equation methods, the mode-I and mode-II stress intensity factors, energy release rate, and crack opening displacements are derived in order to examine several important fracture mechanisms involved in the Smart-Cut process. The effects of defect interaction and stiffening wafer on defect growth are investigated. The numerical results indi- cate that a stiffener/handle wafer can effectively prevent the donor wafer from blistering and exfoliation, but it slows down the defect growth by decreasing the magnitudes of SIF＇s. Defect interaction also plays an important role in the splitting process of SOI wafers, but its contribution depends strongly on the size, interval and internal pressure of defects. Finally, an analytical formula is derived to estimate the implantation dose required for splitting a SOI wafer.展开更多
With the increasing demand for energy,traditional oil resources are facing depletion and insufficient supply.Many countries are rapidly turning to the development of unconventional oil and gas resources.Among them,sha...With the increasing demand for energy,traditional oil resources are facing depletion and insufficient supply.Many countries are rapidly turning to the development of unconventional oil and gas resources.Among them,shale oil and gas reservoirs have become the focus of unconventional oil and gas resources exploration and development.Based on the characteristics of shale oil and gas reservoirs,supercritical CO_(2) fracturing is more conducive to improving oil recovery than other fracturing technologies.In this paper,the mechanism of fracture initiation and propagation of supercritical CO_(2) in shale is analyzed,including viscosity effect,surface tension effect,permeation diffusion effect of supercritical CO_(2),and dissolution-adsorption effect between CO_(2) and shale.The effects of natural factors,such as shale properties,bedding plane and natural fractures,and controllable factors,proppant,temperature,pressure,CO_(2) concentration and injection rate on fracture initiation and propagation are clarified.The methods of supercritical CO_(2) fracturing process,thickener and proppant optimization to improve the efficiency of supercritical CO_(2) fracturing are discussed.In addition,some new technologies of supercritical CO_(2) fracturing are introduced.The challenges and prospects in the current research are also summarized.For example,supercritical CO_(2) is prone to filtration when passing through porous media,and it is difficult to form a stable flow state.Therefore,in order to achieve stable fracturing fluid suspension and effectively support fractu res,it is urge nt to explo re new fracturing fluid additives or improve fracturing fluid formulations combined with the research of new proppants.This paper is of great significance for understanding the behavior mechanism of supercritical CO_(2) in shale and optimizing fracturing technology.展开更多
In Part 2 of the paper on the Smart-Cut process, the effects of bonding flaws characterized by the size and internal pressure before and after splitting are studied by using fracture mechanics models. It is found that...In Part 2 of the paper on the Smart-Cut process, the effects of bonding flaws characterized by the size and internal pressure before and after splitting are studied by using fracture mechanics models. It is found that the bonding flaws with large size are prone to cause severe deviation of defect growth, leading to a non-transferred area of thin layer when splitting. In a practical Smart-Cut process where the internal pressure of bonding flaws is very small, large interfacial defects always promote defect growth in the splitting process. Meanwhile, increasing the internal pressure of the bonding flaws decreases the defect growth and its deviation before splitting. The mechanism of relaxation of stiffener constraint is proposed to clarify the effect of bonding flaws. Moreover, the progress of the splitting process is analyzed when bonding flaws are present. After splitting, those bonding flaws with large size and high internal pressure are vulnerable for the blistering of the thin film during high-temperature annealing.展开更多
To solve the problem that the production of Mahu conglomerate reservoir is not up to expectation after the multi-cluster plus temporary plugging fracturing technology is applied in horizontal wells, stages 2–6 in the...To solve the problem that the production of Mahu conglomerate reservoir is not up to expectation after the multi-cluster plus temporary plugging fracturing technology is applied in horizontal wells, stages 2–6 in the test well MaHW6285 are selected to carry out erosion tests with different pumping parameters. The downhole video imaging technology is used to monitor the degree of perforations erosion, and then the fracture initiation and proppant distribution of each cluster are analyzed. The results showed that proppant entered 76.7% of the perforations. The proppant was mainly distributed in a few perforation clusters, and the amount of proppant entered in most of the clusters was limited. The proppant distribution in Stage 4 was relatively uniform, and the fracture initiation of each cluster in the stage is more uniform. The proppant distribution in stages 2, 3, 5, and 6 was significantly uneven, and the uniform degree of fracture initiation in each cluster is low. More than 70% of the proppant dose in the stage entered clusters near the heel end, so the addition of diverters did not promote the uniform initiation of hydraulic fractures. There was a positive correlation between the amount of proppant added and the degree of perforations erosion, and the degree of perforations erosion ranged from 15% to 352%, with an average value of 74.5%, which was far higher than the statistical results of shale reservoir tests in North America. The use of 180° phase perforation(horizontal direction) can reduce the “Phase Bias” of perforations erosion, promote uniform perforations erosion and fluid inflow. The research results provide the basis for optimizing the pumping procedure, reducing the perforation erosion and improving the success rate of diversion.展开更多
sing the natural limestone samples taken from the field with dimension of 500 mm×500 mm×1 000 mm, the D-D (dilatancy-diffusion) seismogeny pattern was modeled under the condition of water injection, which ob...sing the natural limestone samples taken from the field with dimension of 500 mm×500 mm×1 000 mm, the D-D (dilatancy-diffusion) seismogeny pattern was modeled under the condition of water injection, which observes the time-space evolutionary features about the relative physics fields of the loaded samples from deformation, formation of microcracks to the occurrence of main rupture. The results of observed apparent resistivity show: ① The process of the deformation from microcrack to main rupture on the loaded rock sample could be characterized by the precursory spatial-temporal changes in the observation of apparent resistivity; ② The precursory temporal changes of observation in apparent resistivity could be divided into several stages, and its spatial distribution shows the difference in different parts of the rock sample; ③ Before the main rupture of the rock sample the obvious ″tendency anomaly′ and ′short-term anomaly″ were observed, and some of them could be likely considered as the ″impending earthquake ″anomaly precursor of apparent resistivity. The changes and distribution features of apparent resistivity show that they are intrinsically related to the dilatancy phenomenon of the loaded rock sample. Finally, this paper discusses the mechanism of resistivity change of loaded rock sample theoretically.展开更多
The study was carried out to improve farmers’ awareness, enhance the adoption of full package sorghum production technologies. The large-scale demonstration was implemented at Gololcha woreda of Arsi zone for one yea...The study was carried out to improve farmers’ awareness, enhance the adoption of full package sorghum production technologies. The large-scale demonstration was implemented at Gololcha woreda of Arsi zone for one year (2019/2020) using Melkam variety. The demonstration was implemented in three kebeles and a total of 100 hectares of land was covered by participating 117 household heads (farmers) out of which 12 of them were women-headed. In the demonstration farmers contributed a land size of 0.25 hectares (the minimum) and 2 hectares of land (maximum). Totally, from the demonstration 4030 quintals of sorghum were harvested with 42.3 quintals per hectare average productivity. The yield obtained by farmers practices w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> 18.23 q</span><span style="font-family:""><span style="font-family:Verdana;">·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> which is lower as compared to the average yield obtained by large scale demonstration. The technology gap (TG) was 15.70 q·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> which indicated that technologies have not been adopted. Extension gap was 24.07 q·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and this result indicated that the extension approach should be </span></span><span style="font-family:Verdana;">more </span><span style="font-family:Verdana;">strengthen</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;">. It has been ascertained that </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">Melkam</span><span style="font-family:Verdana;">”</span><span style="font-family:Verdana;"> variety is the best fitted variety and promotion of improved sorghum technologies via large scale demonstration has show</span><span style="font-family:Verdana;">n</span><span style="font-family:Verdana;"> a considerable yield increment as compared to farmers practices. According to the farmers’ trait preference, Melkam variety was preferred by farmers because of its high yielding, consumption quality, early maturity, palatability, and drought-tolerant traits respectively. For sustainable production of improved sorghum technologies, the seed system should be taken into consideration to deliver the seed supply for the entire sorghum producers.展开更多
There are abundant natural gas resources in the marine shale gas reservoir of Middle Ordovician Wulalike Formation in the Ordos Basin,which is an important resource base for PetroChina Changqing Oilfield Company to in...There are abundant natural gas resources in the marine shale gas reservoir of Middle Ordovician Wulalike Formation in the Ordos Basin,which is an important resource base for PetroChina Changqing Oilfield Company to increase the reserves and production of oil and gas.Compared with the other shale gas reservoirs at home and aboard,however,the marine shale gas reservoir of Middle Ordovician Wulalike Formation in the Ordos Basin has a lower formation pressure coefficient and poorer reservoir physical properties and gas-bearing property,so its production increase difficulty is higher.In this paper,horizontal-well volume fracturing was studied and tested based on the earlier vertical well tests.According to the technical idea of the staged multi-cluster massive fracturing of long horizontal section,the propagation mechanisms and morphological characteristics of fractures were studied and analyzed based on the fracturing geological characteristics of the shale gas reservoir in the Ordos Basin.On this basis,a full three-dimensional fracture model was optimally established for parameter optimization.The fracturing of the test well ZP1 was carried out with 15 stages and 103 clusters.After the fracturing,a more complex fracture network was formed with a fracture complexity index of 0.4-0.6.The microseismic monitoring zone is 579 m long and 266 m wide and the fracture is 146 m high.To address the drainage difficulty after large-volume fracturing of low-pressure shale gas in the Ordos Basin,this paper carries out a gas energized fracturing test.Considering the characteristics of reservoir physical properties,gas-bearing property and segmented fractures,805 m3 liquid nitrogen was injected in stages during the fracturing of the test horizontal well.The formation pressure coefficient measured from pressure buildup data is increased from 0.7 to 0.8 to 1.88.The wellbore gaseliquid flow model was established and the parameters of long-period controlpressure drainage were optimized.The critical surface equipment was upgraded to achieve accurate measurement,safety and environmental protection.And the following research and practice results were obtained.First,based on the technological innovation and optimization,continuous gaseliquid two-phase flow is realized in the test well ZP1 and its production rate and pressure during the test are stable with the tested daily shale gas production at the wellhead of 6.42×10^(4)m^(3).Second,after fracturing,the absolute open flow of the test well reaches 26.4×10^(4)m^(3)/d,which is more than 10 times higher than the production rate of the vertical well in the same block during the test.Thus,a significant breakthrough is realized in the exploration of marine shale gas in North China.展开更多
Considering the danger of water inrush in mining very thick coal seam under water-rich roof in Majialiang Coal Mine,the universal discrete element(UDEC)software was used to simulate the overburden fracture evolution l...Considering the danger of water inrush in mining very thick coal seam under water-rich roof in Majialiang Coal Mine,the universal discrete element(UDEC)software was used to simulate the overburden fracture evolution laws when mining 4#coal seam.Besides,this study researched on the influence of face advancing length,speed and mining height on the height of the water flowing fractured zones(HWFFZ),and analyzed the correlation of face advancing length and change rules of aquifer water levels and goaf water inflow.Based on those mentioned above,this research proposed the following water-controlling technologies:draining the roof water before mining,draining goaf water,reasonable advancing speed and mining thickness.These water-controlling technologies were successfully used in the feld,thus ensured safely mining the very thick coal seam under water-rich roof.展开更多
By reviewing the development history of shale oil reservoir stimulation technology of PetroChina Company Limited(PetroChina),we have systematically summarized the main progress of shale oil reservoir stimulation techn...By reviewing the development history of shale oil reservoir stimulation technology of PetroChina Company Limited(PetroChina),we have systematically summarized the main progress of shale oil reservoir stimulation technology of CNPC in five aspects:reservoir stimulation mechanism,fracture-controlled fracturing,geological-engineering integrated reservoir stimulation design platform,low-cost materials,and large well-pad three-dimensional development mode.It is made clear that the major stimulation technology for shale oil reservoir is the high density multi-cluster and fracture-controlled staged fracturing aiming to increase fracture-controlled reserves,lower operation costs and increase economic benefits.Based on comprehensive analysis of the challenges shale oil reservoir stimulation technology faces in three-dimensional development,stimulation parameter optimization for fracture-controlled fracturing,refracturing and low-cost stimulation technology,we proposed five development directions of the stimulation technology:(1)Strengthen the research on integration of geology and engineering to make full use of reservoir stimulation.(2)Deepen the study on fracture-controlled fracturing to improve reserves development degree.(3)Promote horizontal well three-dimensional development of shale oil to realize the production of multiple layers vertically.(4)Research refracturing technology of shale oil reservoir through horizontal well to efficiently tap the remaining reserves between fractures.(5)Develop low-cost stimulation supporting technology to help reduce the cost and increase economic benefit of oilfield development.展开更多
By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and develop...By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and development difficulties of shale oil in the Jiyang continental rift lake basin,East China,the development technology system suitable for the geological characteristics of shale oil in continental rift lake basins has been primarily formed through innovation and iteration of the development,drilling and fracturing technologies.The technology system supports the rapid growth of shale oil production and reduces the development investment cost.By comparing it with the shale oil development technology in the United States,the prospect of the shale oil development technology iteration in continental rift lake basins is proposed.It is suggested to continuously strengthen the overall three-dimensional development,improve the precision level of engineering technology,upgrade the engineering technical indicator system,accelerate the intelligent optimization of engineering equipment,explore the application of complex structure wells,form a whole-process integrated quality management system from design to implementation,and constantly innovate the concept and technology of shale oil development,so as to promote the realization of extensive,beneficial and high-quality development of shale oil in continental rift lake basins.展开更多
文摘The core sampling experiments were conducted after hydraulic fracturing in the three-dimensional development zone of Fuling shale gas.Six coring wells of different well types were systematically designed.Based on the integrated engineering technology of post-fracturing drilling,coring and monitoring of shale and the analysis of fracture source tracing,the evaluation of the fracture network after fracturing in the three-dimensional development of shale gas was conducted.The data of core fractures after fracturing indicate that three major types of fractures are formed after fracturing:natural fractures,hydraulic fractures,and fractures induced by external mechanical force,which are further classified into six subcategories:natural structural fractures,natural bedding fractures,hydraulic fractures,hydraulically activated fractures,drilling induced fractures,and fractures induced by core transportation.The forms of the artificial fracture network after fracturing are complex.Hydraulic fractures and hydraulically activated fractures interweave with each other,presenting eight forms of artificial fracture networks,among which the“一”-shaped fracture is the most common,accounting for approximately 70%of the total fractures.When the distance to the fractured wellbore is less than 35 m,the density of the artificial fracture network is relatively high;when it is 35–100 m,the density is lower;and when it is beyond 100 m,the density gradually increases.The results of the fracture tracing in the core sampling area confirm that the current fracturing technology can essentially achieve the differential transformation of the reservoir in the main area of Jiaoshiba block in Fuling.The three-layer three-dimensional development model can efficiently utilize shale gas reserves,although there is still room for improvement in the complexity and propagation uniformity of fractures.It is necessary to further optimize technologies such as close-cutting combined with temporary blocking and deflection within fractures or at fracture mouths,as well as limited flow perforation techniques,to promote the balanced initiation and extension of fractures.
基金supported by the National Key Research and Development Program of China (Grant No.2020YFC1808104)the National Natural Science Foundation of China (Grant Nos.42227804 and 41931289).
文摘Due to severe mass transfer limitations,contaminated soils with low-permeability limit the accessibility of amendments,resulting in less effective or even ineffective remediation.Enhancing the mass transfer properties of low-permeability soils by hydraulic fracturing is a promising technique.A quasi-three-dimensional(quasi-3D)analytical model was presented that accounted for advection-diffusion-adsorption-degradation processes in the fracture-matrix system.The model combined the injection-extraction technique to investigate the enhanced transport of amendments in low-permeability contaminated soil by hydraulic fractures.Then,the injection strategy and controllable parameter optimization were comprehensively studied by analyzing the radial transport behavior of the amendment within hydraulic fractures.The results showed that higher injection volumetric rates accelerated the formation of a uniform line source within the fractures.Although the differences in the effective ratio of the amendment among different injection modes were not significant,considering the amendment utilization rate and cost reduction,the recommended injection strategy was the combination of continuous pulsing injection and periodic injection.
基金support of the Key Program of National Natural Science Foundation of China(51736009)National Natural Science Foundation of China(51676196,51976228)+4 种基金Guangdong Special Support Program(2019BT02L278)Frontier Sciences Key Research Program of the Chinese Academy of Sciences(QYZDJSSW-JSC033,QYZDB-SSW-JSC028,ZDBS-LY-SLH041)Science and Technology Apparatus Development Program of the Chinese Academy of Sciences(YZ201619)the National Key R&D Program of China(2017YFC0307306)Special Project for Marine Economy Development of Guangdong Province(GDME-2018D002,GDME-2020D044)。
文摘Low temperature and low permeability are the challenges for the development of hydrate reservoirs in permafrost.The ice produced around the production well caused by high depressurization driving force reduces the gas production,and it is necessary to reduce the effect of ice production on gas production.In this work,a new combination of fracturing technology and depressurization method was proposed to evaluate the gas production potential at the site DK-2 in Qinghai-Tibet Plateau Permafrost.A relatively higher intrinsic permeability of the fracture zone surround the horizontal production well was created by the fracturing technology.The simulation results showed that the fracture zone reduced the blocking of production ice to production wells and promoted the propagation of production pressure.And the gas production increased by 2.1 times as the radius of the fracture zone increased from 0 to 4 m in 30 years.Nearly half of the hydrate reservoirs were dissociated in 30 years,and greater than 51.7%of the gas production was produced during the first 10 years.Moreover,production behaviours were sensitive to the depressurization driving force but not to the thermal conductivity.The growth of gas production was not obvious with the intrinsic permeability of the fracture zone higher than 100 m D.The effect of ice production on gas production by fracturing technology and depressurization method was limited.
基金National key R&D plan(2016YFC060110605)National major projects(2016ZX05034004-005)。
文摘Hydraulic fracturing technology is an important means of shale gas development,and microseismic monitoring is the key technology of fracturing effect evaluation.In this study,hydraulic fracturing and microseismic monitoring were simultaneously conducted in the Eyangye 2HF well(hereinafter referred to as EYY2HF well).The target stratum of this well is the second member of the Doushantuo Formation of the Sinian System,which is the oldest stratum of horizontal shale gas wells in the world.A total of 4341 microseismic fracturing events were identified,and 23 fracturing stages of the well were defined.The fluctuation of the number of events showed a repeating“high-low”pattern,and the average energy of these events showed minimal differences.These findings indicate that the water pressure required for the reconstruction of the EYY2HF well is appropriate.The main body of the fracture network extended from northwest to southeast,consistent with the interpretation of regional geological and seismic data.The stimulated rock volumes showed a linear increase with the increase of the fracturing stage.Some technological measures,such as quick lift displacement,quick lift sand ratio,and pump stop for secondary sand addition,were adopted during fracturing to increase the complexity of the fracture network.Microseismic fracture monitoring of the well achieved expected eff ects and guided real-time fracturing operations and fracturing eff ect evaluation.
文摘The reservoir depthi ranges from 2300 m to 3950 m.It is of 14 sand formations that consist of 28 layers,of which 24 layers have a thickness of 5-20 m.Mainly composed of feldspar.quartz silt and fine sandstones.the reservoir is affected by com-paction,leading to poor physical properties.Core analysis indicates that the S:interval has a porosity of 17.4%.an air permeability of 50X 10 pμm’,a shale content of 7.2%.carbonate content of 5.3%,and median grain diameter of 0.19 mm.
文摘Limited by serious heterogeneity both horizontally and vertically, water driving of low-permeability layers in Qiaokou oilfield appears to be very difficult. As the classⅠ layer reaches the stage of high water-content too early, the level of exploitation became worse with low-recovery. Regarding the serious heterogeneity and low recovery in layers class Ⅱand Ⅲ, composite fracturing technology suitable for this kind of reservoir was applied. Its basement was a lab study of indoor water driving efficiency and fracturing experiment. Perfect result has achieved by using the technology.
文摘Shale gas is a kind of environmentally friendly energy difference between the conventional natural gas, shale gas in shale interlayer containing mineral machine quality, most distributed in the basin topography, shale interlayer thickness is bigger, is because between rock and rock cracks and voids, save for a long time, biological decomposition, degradation. There is also a very small amount of shale gas dissolved in asphaltenes and kerogen. Domestic shale gas resources are very rich, and its utilization can reduce the emission of other polluting gases, but there are certain risks in the exploitation of shale gas. For this, this paper makes a detailed study on the pressure technology and the performance of fracturing oil for the exploitation of shale gas at home and abroad, and analyzes in detail the characteristics, application methods and application scope of various fracturing technologies, which also briefly describes the current development status of shale gas.
基金The 2023 Guangxi University Young and Middle-Aged Teachers’Scientific Research Basic Ability Improvement Project“Research on Seismic Performance of Prefabricated CFST Column-SRC Beam Composite Joints”(2023KY1204)The 2023 Guangxi Vocational Education Teaching Reform Research Project“Research and Practice on the Cultivation of Digital Talents in Prefabricated Buildings in the Context of Deepening the Integration of Industry and Education”(GXGZJG2023B052)The 2022 Guangxi Polytechnic of Construction School-Level Teaching Innovation Team Project“Prefabricated and Intelligent Teaching Innovation Team”(Gui Jian Yuan Ren[2022]No.15)。
文摘This paper discusses the digital application and benefit analysis of building information model(BIM)technology in the large-scale comprehensive development project of the Guangxi headquarters base.The project covers a total area of 92,100 square meters,with a total construction area of 379,700 square meters,including a variety of architectural forms.Through three-dimensional modeling and simulation analysis,BIM technology significantly enhances the design quality and efficiency,shortens the design cycle by about 20%,and promotes the collaboration and integration of project management,improving the management efficiency by about 25%.During the construction phase,the collision detection and four-dimensional visual management functions of BIM technology have improved construction efficiency by about 15%and saved the cost by about 10%.In addition,BIM technology has promoted green building and sustainable development,achieved the dual improvement of technical and economic indicators and social and economic benefits,set an example for enterprises in digital transformation,and opened up new market businesses.
基金supported by the key project of the United Foun-dation of National NaturalScience Foundation of China“Basic Research on Volumetric Acid Fracturing of Deep Sulfur-bearing Carbonate Gas Reservoirs in Sichuan Basin”(No.U21A20105)CNPC Science and Technology Innovation Project"Research on the Mechanism of Complex Fracture Propagation and Control Measures of Temporary Plugging Fracturing of Shale Gas Reservoir"(No.2020D-5007-0208).
文摘There are abundant tight sandstone gas resources in the Sichuan Basin,which are the important objects of reserve and production increase and large-scale development.Due to their discontinuous sandbody distribution,narrow channels,and strong horizontal and vertical heteroge-neity,however,conventional fracturing technologies cannot achieve the ideal stimulation effect here.In order to address this difficulty,this paper dissects the geology engineering characteristics of tight sandstone gas reservoirs in the western Sichuan Basin.Starting from the seepage mechanics theory,the concept of“multi-scale high-density”tight gas fracturing technology is put forward by fully referring to the experience of previous multi-round reservoir stimulation in the western Sichuan Basin and the idea of unconventional volume fracturing technology.In addition,its conceptual connotation,key technologies and implementation effects are illustrated.The following research results are obtained.First,the seepage characteristics make it necessary for the efficient production of tight gas reserves to increase fracture density and stimulated reservoir volume(SRV).Second,the“multi-scale high-density”fracturing technology emphasizes the rationality of high-density hydraulic fracture creation and the matching of multi-scale fractureflow capacity,and aims at establishing a multi-level fracture system with effective and steady gasflow in tight reservoirs through fracturing.Third,the“wide,dense,support,stable,and precise”fracturing technology is applied to improve single well production and estimated ultimate recovery(EUR).Fourth,the engineering practice of“multi-scale high-density”fracturing technology in the tight reservoirs of Jurassic Shaximiao Formation and Triassic Xujiahe Formation in the ZJ Gas Field realizes the average single well production rate of 15.6104 m3/d,which is 1.96 times higher than that before the stimulation.Obviously,it provides powerful support for the operation of the ZJ Gas Field into a giant gasfield with the reserves of 100 billion cubic meters.In conclusion,the formation of the concept and key technologies of“multi-scale high-density”fracturing technology effectively supports the efficient development of tight gas in the western Sichuan Basin and points out the following research direction of tight gas reservoir stimulation.The research results provide reference and guidance for the large-scale benefit development of tight gas in China.
文摘Grid-level large-scale electrical energy storage(GLEES) is an essential approach for balancing the supply–demand of electricity generation, distribution, and usage. Compared with conventional energy storage methods, battery technologies are desirable energy storage devices for GLEES due to their easy modularization, rapid response, flexible installation, and short construction cycles. In general, battery energy storage technologies are expected to meet the requirements of GLEES such as peak shaving and load leveling, voltage and frequency regulation, and emergency response, which are highlighted in this perspective. Furthermore, several types of battery technologies, including lead–acid, nickel–cadmium, nickel–metal hydride, sodium–sulfur, lithium-ion, and flow batteries, are discussed in detail for the application of GLEES. Moreover, some possible developing directions to facilitate efforts in this area are presented to establish a perspective on battery technology, provide a road map for guiding future studies, and promote the commercial application of batteries for GLEES.
基金the Australian Research Council (ARC),the National Natural Science Foundation of China (10525210 and 10732050) 973 Project (2004CB619303)
文摘In the present paper, continuum fracture mechanics is used to analyze the Smart-Cut process, a recently established ion cut technology which enables highly efficient fabrication of various silicon-on-insulator （SOI） wafers of high uniformity in thickness. Using integral transform and Cauchy singular integral equation methods, the mode-I and mode-II stress intensity factors, energy release rate, and crack opening displacements are derived in order to examine several important fracture mechanisms involved in the Smart-Cut process. The effects of defect interaction and stiffening wafer on defect growth are investigated. The numerical results indi- cate that a stiffener/handle wafer can effectively prevent the donor wafer from blistering and exfoliation, but it slows down the defect growth by decreasing the magnitudes of SIF＇s. Defect interaction also plays an important role in the splitting process of SOI wafers, but its contribution depends strongly on the size, interval and internal pressure of defects. Finally, an analytical formula is derived to estimate the implantation dose required for splitting a SOI wafer.
文摘With the increasing demand for energy,traditional oil resources are facing depletion and insufficient supply.Many countries are rapidly turning to the development of unconventional oil and gas resources.Among them,shale oil and gas reservoirs have become the focus of unconventional oil and gas resources exploration and development.Based on the characteristics of shale oil and gas reservoirs,supercritical CO_(2) fracturing is more conducive to improving oil recovery than other fracturing technologies.In this paper,the mechanism of fracture initiation and propagation of supercritical CO_(2) in shale is analyzed,including viscosity effect,surface tension effect,permeation diffusion effect of supercritical CO_(2),and dissolution-adsorption effect between CO_(2) and shale.The effects of natural factors,such as shale properties,bedding plane and natural fractures,and controllable factors,proppant,temperature,pressure,CO_(2) concentration and injection rate on fracture initiation and propagation are clarified.The methods of supercritical CO_(2) fracturing process,thickener and proppant optimization to improve the efficiency of supercritical CO_(2) fracturing are discussed.In addition,some new technologies of supercritical CO_(2) fracturing are introduced.The challenges and prospects in the current research are also summarized.For example,supercritical CO_(2) is prone to filtration when passing through porous media,and it is difficult to form a stable flow state.Therefore,in order to achieve stable fracturing fluid suspension and effectively support fractu res,it is urge nt to explo re new fracturing fluid additives or improve fracturing fluid formulations combined with the research of new proppants.This paper is of great significance for understanding the behavior mechanism of supercritical CO_(2) in shale and optimizing fracturing technology.
基金supported by the Australian Research Council (ARC), the National Natural Science Foundation of China (10525210 and 10732050) 973 Project (2004CB619303)
文摘In Part 2 of the paper on the Smart-Cut process, the effects of bonding flaws characterized by the size and internal pressure before and after splitting are studied by using fracture mechanics models. It is found that the bonding flaws with large size are prone to cause severe deviation of defect growth, leading to a non-transferred area of thin layer when splitting. In a practical Smart-Cut process where the internal pressure of bonding flaws is very small, large interfacial defects always promote defect growth in the splitting process. Meanwhile, increasing the internal pressure of the bonding flaws decreases the defect growth and its deviation before splitting. The mechanism of relaxation of stiffener constraint is proposed to clarify the effect of bonding flaws. Moreover, the progress of the splitting process is analyzed when bonding flaws are present. After splitting, those bonding flaws with large size and high internal pressure are vulnerable for the blistering of the thin film during high-temperature annealing.
基金Supported by the PetroChina–China University of Petroleum (Beijing) Strategic Cooperation Project (ZLZX2020-04)。
文摘To solve the problem that the production of Mahu conglomerate reservoir is not up to expectation after the multi-cluster plus temporary plugging fracturing technology is applied in horizontal wells, stages 2–6 in the test well MaHW6285 are selected to carry out erosion tests with different pumping parameters. The downhole video imaging technology is used to monitor the degree of perforations erosion, and then the fracture initiation and proppant distribution of each cluster are analyzed. The results showed that proppant entered 76.7% of the perforations. The proppant was mainly distributed in a few perforation clusters, and the amount of proppant entered in most of the clusters was limited. The proppant distribution in Stage 4 was relatively uniform, and the fracture initiation of each cluster in the stage is more uniform. The proppant distribution in stages 2, 3, 5, and 6 was significantly uneven, and the uniform degree of fracture initiation in each cluster is low. More than 70% of the proppant dose in the stage entered clusters near the heel end, so the addition of diverters did not promote the uniform initiation of hydraulic fractures. There was a positive correlation between the amount of proppant added and the degree of perforations erosion, and the degree of perforations erosion ranged from 15% to 352%, with an average value of 74.5%, which was far higher than the statistical results of shale reservoir tests in North America. The use of 180° phase perforation(horizontal direction) can reduce the “Phase Bias” of perforations erosion, promote uniform perforations erosion and fluid inflow. The research results provide the basis for optimizing the pumping procedure, reducing the perforation erosion and improving the success rate of diversion.
文摘sing the natural limestone samples taken from the field with dimension of 500 mm×500 mm×1 000 mm, the D-D (dilatancy-diffusion) seismogeny pattern was modeled under the condition of water injection, which observes the time-space evolutionary features about the relative physics fields of the loaded samples from deformation, formation of microcracks to the occurrence of main rupture. The results of observed apparent resistivity show: ① The process of the deformation from microcrack to main rupture on the loaded rock sample could be characterized by the precursory spatial-temporal changes in the observation of apparent resistivity; ② The precursory temporal changes of observation in apparent resistivity could be divided into several stages, and its spatial distribution shows the difference in different parts of the rock sample; ③ Before the main rupture of the rock sample the obvious ″tendency anomaly′ and ′short-term anomaly″ were observed, and some of them could be likely considered as the ″impending earthquake ″anomaly precursor of apparent resistivity. The changes and distribution features of apparent resistivity show that they are intrinsically related to the dilatancy phenomenon of the loaded rock sample. Finally, this paper discusses the mechanism of resistivity change of loaded rock sample theoretically.
文摘The study was carried out to improve farmers’ awareness, enhance the adoption of full package sorghum production technologies. The large-scale demonstration was implemented at Gololcha woreda of Arsi zone for one year (2019/2020) using Melkam variety. The demonstration was implemented in three kebeles and a total of 100 hectares of land was covered by participating 117 household heads (farmers) out of which 12 of them were women-headed. In the demonstration farmers contributed a land size of 0.25 hectares (the minimum) and 2 hectares of land (maximum). Totally, from the demonstration 4030 quintals of sorghum were harvested with 42.3 quintals per hectare average productivity. The yield obtained by farmers practices w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> 18.23 q</span><span style="font-family:""><span style="font-family:Verdana;">·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> which is lower as compared to the average yield obtained by large scale demonstration. The technology gap (TG) was 15.70 q·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> which indicated that technologies have not been adopted. Extension gap was 24.07 q·ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> and this result indicated that the extension approach should be </span></span><span style="font-family:Verdana;">more </span><span style="font-family:Verdana;">strengthen</span><span style="font-family:Verdana;">ed</span><span style="font-family:Verdana;">. It has been ascertained that </span><span style="font-family:Verdana;">“</span><span style="font-family:Verdana;">Melkam</span><span style="font-family:Verdana;">”</span><span style="font-family:Verdana;"> variety is the best fitted variety and promotion of improved sorghum technologies via large scale demonstration has show</span><span style="font-family:Verdana;">n</span><span style="font-family:Verdana;"> a considerable yield increment as compared to farmers practices. According to the farmers’ trait preference, Melkam variety was preferred by farmers because of its high yielding, consumption quality, early maturity, palatability, and drought-tolerant traits respectively. For sustainable production of improved sorghum technologies, the seed system should be taken into consideration to deliver the seed supply for the entire sorghum producers.
基金Project supported by the National Major Science and Technology Project“Development Demonstration Project of Large-scale Low-permeability Lithologic-Stratigraphic Reservoirs in the Ordos Basin”(No.2016ZX05050)。
文摘There are abundant natural gas resources in the marine shale gas reservoir of Middle Ordovician Wulalike Formation in the Ordos Basin,which is an important resource base for PetroChina Changqing Oilfield Company to increase the reserves and production of oil and gas.Compared with the other shale gas reservoirs at home and aboard,however,the marine shale gas reservoir of Middle Ordovician Wulalike Formation in the Ordos Basin has a lower formation pressure coefficient and poorer reservoir physical properties and gas-bearing property,so its production increase difficulty is higher.In this paper,horizontal-well volume fracturing was studied and tested based on the earlier vertical well tests.According to the technical idea of the staged multi-cluster massive fracturing of long horizontal section,the propagation mechanisms and morphological characteristics of fractures were studied and analyzed based on the fracturing geological characteristics of the shale gas reservoir in the Ordos Basin.On this basis,a full three-dimensional fracture model was optimally established for parameter optimization.The fracturing of the test well ZP1 was carried out with 15 stages and 103 clusters.After the fracturing,a more complex fracture network was formed with a fracture complexity index of 0.4-0.6.The microseismic monitoring zone is 579 m long and 266 m wide and the fracture is 146 m high.To address the drainage difficulty after large-volume fracturing of low-pressure shale gas in the Ordos Basin,this paper carries out a gas energized fracturing test.Considering the characteristics of reservoir physical properties,gas-bearing property and segmented fractures,805 m3 liquid nitrogen was injected in stages during the fracturing of the test horizontal well.The formation pressure coefficient measured from pressure buildup data is increased from 0.7 to 0.8 to 1.88.The wellbore gaseliquid flow model was established and the parameters of long-period controlpressure drainage were optimized.The critical surface equipment was upgraded to achieve accurate measurement,safety and environmental protection.And the following research and practice results were obtained.First,based on the technological innovation and optimization,continuous gaseliquid two-phase flow is realized in the test well ZP1 and its production rate and pressure during the test are stable with the tested daily shale gas production at the wellhead of 6.42×10^(4)m^(3).Second,after fracturing,the absolute open flow of the test well reaches 26.4×10^(4)m^(3)/d,which is more than 10 times higher than the production rate of the vertical well in the same block during the test.Thus,a significant breakthrough is realized in the exploration of marine shale gas in North China.
基金provided by the Priority Academic Program Development of Jiangsu Higher Education Institutions of China(No.SZBF2011-6-B35)the Fundamental Research Funds for the Central Universities of China(No.2012LWB42)
文摘Considering the danger of water inrush in mining very thick coal seam under water-rich roof in Majialiang Coal Mine,the universal discrete element(UDEC)software was used to simulate the overburden fracture evolution laws when mining 4#coal seam.Besides,this study researched on the influence of face advancing length,speed and mining height on the height of the water flowing fractured zones(HWFFZ),and analyzed the correlation of face advancing length and change rules of aquifer water levels and goaf water inflow.Based on those mentioned above,this research proposed the following water-controlling technologies:draining the roof water before mining,draining goaf water,reasonable advancing speed and mining thickness.These water-controlling technologies were successfully used in the feld,thus ensured safely mining the very thick coal seam under water-rich roof.
基金Supported by the National Science and Technology Major Project(2016ZX05023,2017ZX05013-005)。
文摘By reviewing the development history of shale oil reservoir stimulation technology of PetroChina Company Limited(PetroChina),we have systematically summarized the main progress of shale oil reservoir stimulation technology of CNPC in five aspects:reservoir stimulation mechanism,fracture-controlled fracturing,geological-engineering integrated reservoir stimulation design platform,low-cost materials,and large well-pad three-dimensional development mode.It is made clear that the major stimulation technology for shale oil reservoir is the high density multi-cluster and fracture-controlled staged fracturing aiming to increase fracture-controlled reserves,lower operation costs and increase economic benefits.Based on comprehensive analysis of the challenges shale oil reservoir stimulation technology faces in three-dimensional development,stimulation parameter optimization for fracture-controlled fracturing,refracturing and low-cost stimulation technology,we proposed five development directions of the stimulation technology:(1)Strengthen the research on integration of geology and engineering to make full use of reservoir stimulation.(2)Deepen the study on fracture-controlled fracturing to improve reserves development degree.(3)Promote horizontal well three-dimensional development of shale oil to realize the production of multiple layers vertically.(4)Research refracturing technology of shale oil reservoir through horizontal well to efficiently tap the remaining reserves between fractures.(5)Develop low-cost stimulation supporting technology to help reduce the cost and increase economic benefit of oilfield development.
基金Supported by the Strategic Research and Technical Consultation Project of Sinopec Science and Technology CommissionSinopec Major Science and Technology Project(P22037)。
文摘By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and development difficulties of shale oil in the Jiyang continental rift lake basin,East China,the development technology system suitable for the geological characteristics of shale oil in continental rift lake basins has been primarily formed through innovation and iteration of the development,drilling and fracturing technologies.The technology system supports the rapid growth of shale oil production and reduces the development investment cost.By comparing it with the shale oil development technology in the United States,the prospect of the shale oil development technology iteration in continental rift lake basins is proposed.It is suggested to continuously strengthen the overall three-dimensional development,improve the precision level of engineering technology,upgrade the engineering technical indicator system,accelerate the intelligent optimization of engineering equipment,explore the application of complex structure wells,form a whole-process integrated quality management system from design to implementation,and constantly innovate the concept and technology of shale oil development,so as to promote the realization of extensive,beneficial and high-quality development of shale oil in continental rift lake basins.
