With the extensive application of polymer flooding technology in offshore oilfields,the plugging in polymer injection wells has become more and more severe,which seriously affects the oil displacement effect and regul...With the extensive application of polymer flooding technology in offshore oilfields,the plugging in polymer injection wells has become more and more severe,which seriously affects the oil displacement effect and regular production of oilfields.In this paper,a new kind of blockage remover has been developed and evaluated by rheological behavior experiments,dissolution experiments and core flooding experiments.The results reveal that this new blockage remover can effectively reduce the viscosity of polymer and completely degrade the reservoir blockage with low corrosion rate.It is beneficial to long-term production of oil wells in offshore oilfield.Results of core flooding experiments show that this new blockage remover can relieve polymer damage and improve permeability.The agent has been applied in LD10-1 oilfield in 2016,the daily injection rate increased significantly after stimulation.展开更多
In order to safely,efficiently and economically remove the blockages of natural gas hydrate(NGH)in the wellbores of ultra-high pressure gas wells,this paper utilized the heat released from an independently developed a...In order to safely,efficiently and economically remove the blockages of natural gas hydrate(NGH)in the wellbores of ultra-high pressure gas wells,this paper utilized the heat released from an independently developed autogenetic heat based solid blockage remover through chemical reaction in the wellbore to dissolve NGH and prevent it from forming again.In addition,adjustable heat generation time and heat generation amount was realized by regulating the dosage of the blockage remover.Finally,the chemically autogenetic heat based blockage removal technology was applied to remove the blockages in ultra-high pressure sour gas wells in the Sichuan Basin.And the following research results were obtained.First,when the independently developed chemically autogenetic heat based solid blockage remover is adopted,the peak temperature(34.2e88.5℃)and time(24.2e884.0 min)of heat generation can be adjusted by its dosage.What's more,there is NGH inhibitor in the reaction product,which can inhibit the regeneration of NGH.Second,as the concentration of the blockage remover increases,the heat transfer speed increases,leading to an increase of NGH dissociation rate around the blockage remover.Third,blockage removal time increases with the increase of wellbore ID.In addition,the increasing rate of the blockage removal time as the wellbore ID increases from 64 mm to 76 mm is lower than that from 76 mm to 102 mm.Fourth,the coincidence rate between the simulation calculation result of heat diffusion and the on-site actual consumption is more than 85%,which indicates that the proposed model for the heat diffusion of chemically autogenetic heat based blockage remover is reliable and can be used to calculate the dosage of blockage remover.Fifth,solid reagent adding device with resistance to sulfur and pressure of 140 MPa is used to add autogenetic heat based solid blockage remover.This blockage remover has been applied in the ultra-high pressure sour gas wells in the Sichuan Basin three well times.Thanks to its application,NGH blockages in these wells are removed successfully and their production is resumed smoothly.In conclusion,this blockage removal technology has such advantages as effective blockage removal,safe and simple on-site operation and low cost,and a promising application prospect.展开更多
It is a common phenomenon during CBM drilling and production that reservoir damage is not eliminated completely.In view of this,a technical idea of composite pulsating hydraulic fracturing of radial horizontal wells w...It is a common phenomenon during CBM drilling and production that reservoir damage is not eliminated completely.In view of this,a technical idea of composite pulsating hydraulic fracturing of radial horizontal wells which is conducive to blockage removing and stimulation was put forward in this paper.Speaking of the hydraulic jetting in a multi-branch radial well,it is to conduct pulsating hydraulic fracturing moderately through a high-diversion radial hole,so as to crush and break coal beds near the main hole to the uttermost.Thus,an extensive pressure relief and permeability increase area where high-diversion pathways are combined with fracture networks is formed.Then,to verify its technical principles,laboratory tests on pulsating hydraulic fracturing of radial wells were designed and carried out.Besides,the relationships of the features of acoustic emission(AE)response during the formation of fractures by composite fracturing of radial horizontal wells vs.coal breaking degree and macro fracture morphology were experimentally studied by using a pulse servo fatigue testing machine and an acoustic emission detector.And the following research results were obtained.First,under experimental conditions,fractures initially occur when the pressure of composite pulsating hydraulic fracturing of radial horizontal wells is 1/3–1/4 of the peak pressure of conventional fracturing,and the amount of its AE events is 1.38–7.07 times that of conventional fracturing.Second,when composite pulsating hydraulic fracturing of radial horizontal wells is conducted,AE emission signals respond strongly,the peak pressure for macro fracturing is lower and a larger fracture network can be generated more easily under the same condition.Third,radial laterals amount,borehole length,dynamic loading frequency and amplitude are the important factors affecting the effect of composite pulsating hydraulic fracturing of radial horizontal wells.In conclusion,composite pulsating hydraulic fracturing of radial horizontal wells provides a new idea of removing the blockages in CBM reservoirs and developing CBM efficiently,realizing effective blockage removing and stimulation of CBM wells.展开更多
Automatic placement and routing technology provides an effective tool for designing simulation and information guidance.Various intelligent algorithms in mechanical design,ocean and ship engineering and aerospace desi...Automatic placement and routing technology provides an effective tool for designing simulation and information guidance.Various intelligent algorithms in mechanical design,ocean and ship engineering and aerospace design have been implemented.However,automatic placement and routing has never been integrated into interactive 3D application.In this paper,idea of combining the interactive 3D application with automatic placement and routing is proposed,and its main issue is discussed.Then we present a new placement and routing algorithm suitable for 3D interactive application containing model design,fundamental algorithm and global optimization to remove routing blockage.Experimental results demonstrate that the proposed algorithm works effectively in simulation,meets the requirements of real-time rendering and has great practical value.展开更多
基金The work is supported by National Science and Technology Major Project of the Ministry of Science and Technology of China“High Efficiency Oil Production and Supporting Technology Demonstration on Bohai Oilfield”(No.2016ZX05058-003).
文摘With the extensive application of polymer flooding technology in offshore oilfields,the plugging in polymer injection wells has become more and more severe,which seriously affects the oil displacement effect and regular production of oilfields.In this paper,a new kind of blockage remover has been developed and evaluated by rheological behavior experiments,dissolution experiments and core flooding experiments.The results reveal that this new blockage remover can effectively reduce the viscosity of polymer and completely degrade the reservoir blockage with low corrosion rate.It is beneficial to long-term production of oil wells in offshore oilfield.Results of core flooding experiments show that this new blockage remover can relieve polymer damage and improve permeability.The agent has been applied in LD10-1 oilfield in 2016,the daily injection rate increased significantly after stimulation.
基金Project supported by the Scientific Research and Technology Development Project of PetroChina Southwest Oil and Gas Field Company“Research on Hydrate plugging removal Technology for Ultra-high pressure Gas Wells”(No.20180303-03).
文摘In order to safely,efficiently and economically remove the blockages of natural gas hydrate(NGH)in the wellbores of ultra-high pressure gas wells,this paper utilized the heat released from an independently developed autogenetic heat based solid blockage remover through chemical reaction in the wellbore to dissolve NGH and prevent it from forming again.In addition,adjustable heat generation time and heat generation amount was realized by regulating the dosage of the blockage remover.Finally,the chemically autogenetic heat based blockage removal technology was applied to remove the blockages in ultra-high pressure sour gas wells in the Sichuan Basin.And the following research results were obtained.First,when the independently developed chemically autogenetic heat based solid blockage remover is adopted,the peak temperature(34.2e88.5℃)and time(24.2e884.0 min)of heat generation can be adjusted by its dosage.What's more,there is NGH inhibitor in the reaction product,which can inhibit the regeneration of NGH.Second,as the concentration of the blockage remover increases,the heat transfer speed increases,leading to an increase of NGH dissociation rate around the blockage remover.Third,blockage removal time increases with the increase of wellbore ID.In addition,the increasing rate of the blockage removal time as the wellbore ID increases from 64 mm to 76 mm is lower than that from 76 mm to 102 mm.Fourth,the coincidence rate between the simulation calculation result of heat diffusion and the on-site actual consumption is more than 85%,which indicates that the proposed model for the heat diffusion of chemically autogenetic heat based blockage remover is reliable and can be used to calculate the dosage of blockage remover.Fifth,solid reagent adding device with resistance to sulfur and pressure of 140 MPa is used to add autogenetic heat based solid blockage remover.This blockage remover has been applied in the ultra-high pressure sour gas wells in the Sichuan Basin three well times.Thanks to its application,NGH blockages in these wells are removed successfully and their production is resumed smoothly.In conclusion,this blockage removal technology has such advantages as effective blockage removal,safe and simple on-site operation and low cost,and a promising application prospect.
基金supported by National Natural Science Foundation of China-General Program“Study on fracturing control mechanism for radial drilling through water jet in coal rocks”(No.:51674275)National Natural Science Foundation of China-Major Program“Theory of safe and quality drilling for shale oil and gas development under the mode of multi-coupling”(No.:51490652)。
文摘It is a common phenomenon during CBM drilling and production that reservoir damage is not eliminated completely.In view of this,a technical idea of composite pulsating hydraulic fracturing of radial horizontal wells which is conducive to blockage removing and stimulation was put forward in this paper.Speaking of the hydraulic jetting in a multi-branch radial well,it is to conduct pulsating hydraulic fracturing moderately through a high-diversion radial hole,so as to crush and break coal beds near the main hole to the uttermost.Thus,an extensive pressure relief and permeability increase area where high-diversion pathways are combined with fracture networks is formed.Then,to verify its technical principles,laboratory tests on pulsating hydraulic fracturing of radial wells were designed and carried out.Besides,the relationships of the features of acoustic emission(AE)response during the formation of fractures by composite fracturing of radial horizontal wells vs.coal breaking degree and macro fracture morphology were experimentally studied by using a pulse servo fatigue testing machine and an acoustic emission detector.And the following research results were obtained.First,under experimental conditions,fractures initially occur when the pressure of composite pulsating hydraulic fracturing of radial horizontal wells is 1/3–1/4 of the peak pressure of conventional fracturing,and the amount of its AE events is 1.38–7.07 times that of conventional fracturing.Second,when composite pulsating hydraulic fracturing of radial horizontal wells is conducted,AE emission signals respond strongly,the peak pressure for macro fracturing is lower and a larger fracture network can be generated more easily under the same condition.Third,radial laterals amount,borehole length,dynamic loading frequency and amplitude are the important factors affecting the effect of composite pulsating hydraulic fracturing of radial horizontal wells.In conclusion,composite pulsating hydraulic fracturing of radial horizontal wells provides a new idea of removing the blockages in CBM reservoirs and developing CBM efficiently,realizing effective blockage removing and stimulation of CBM wells.
基金supported by the National High-Technology Research and Development Program of China (Grant No.2007AA01Z319)the National Natural Science Foundation of China (Grant No.60873130)the Key Discipline Development Program of Shanghai Municipal Education Commission (Grant No.J50104)
文摘Automatic placement and routing technology provides an effective tool for designing simulation and information guidance.Various intelligent algorithms in mechanical design,ocean and ship engineering and aerospace design have been implemented.However,automatic placement and routing has never been integrated into interactive 3D application.In this paper,idea of combining the interactive 3D application with automatic placement and routing is proposed,and its main issue is discussed.Then we present a new placement and routing algorithm suitable for 3D interactive application containing model design,fundamental algorithm and global optimization to remove routing blockage.Experimental results demonstrate that the proposed algorithm works effectively in simulation,meets the requirements of real-time rendering and has great practical value.
