During hydraulic fracturing operations of low-permeability reservoirs,packers are the key component to ensure the success of multistage fracturing.Packers enable sections of the wellbore to be sealed off and separatel...During hydraulic fracturing operations of low-permeability reservoirs,packers are the key component to ensure the success of multistage fracturing.Packers enable sections of the wellbore to be sealed off and separately fractured by hydraulic pressure,one at a time,while the remainder of the wellbore is not affected.However,reliable sealing properties of the packer rubber are required to meet the high-pressure and high-temperature(HPHT)conditions of reservoirs(such as 70 MPa and 170 ℃).In this study,the structures of the packer rubber with two different materials are optimized numerically by ABAQUS and validated by experiments.The optimization process starts from the packer rubber with a conventional structure,and then,the weakest spots are identified by ABAQUS and improved by slightly varying its structure.This process is iterative,and the final optimized structure of a single rubber barrel with expanding back-up rings is achieved.For the structure of three rubber barrels with metallic protective covers,both HNBR and AFLAS fail under HPHT conditions.For the final optimized structure,the packer rubber made of AFLAS can work better under HPHT than that made of HNBR which ruptures after setting.The results show that the optimized structure of a single rubber barrel with expanding back-up rings and the material AFLAS are a good combination for the packer rubber playing an excellent sealing performance in multistage fracturing in horizontal wells.展开更多
Double packer equipment for hydraulic test can be used to measure pressure of test zone directly, and it is frequently used to perform many kinds of hydraulic tests and take groundwater sample from borehole. The test ...Double packer equipment for hydraulic test can be used to measure pressure of test zone directly, and it is frequently used to perform many kinds of hydraulic tests and take groundwater sample from borehole. The test method of this equipment mainly includes the test design, implementation, interpretation and synthetic analysis. By adopting the double packer equipment for hydraulic test, the parameter distribution of rock permeability along borehole can be acquired, as well as the connectivity, water conductivity and water bearing capacity of the disclosed structure and the chemical characteristics of the deep groundwater. It is a necessary method for the research and evaluation of the complex hypotonicity terrace site selection under geological conditions. This method is not only suitable for the geological disposal of high level radioactive waste, but also can be used in the site selection of underground facilities such as storage of petroleum and carbon dioxide. Meanwhile, it has a good application prospect in other hydrogeological investigation fields.展开更多
Usually the water head of the pumped storage hydro-plant is high, generally up to 400-500 m, therefore the rock mass under the high-pressure bifurcation pipe have to bear as high as millions Pascal water pressure, in ...Usually the water head of the pumped storage hydro-plant is high, generally up to 400-500 m, therefore the rock mass under the high-pressure bifurcation pipe have to bear as high as millions Pascal water pressure, in according with the requirements of high water head pumped storage hydro-plant should be 1.2 times of the water head special high-pressure packer permeability test compared with normal to test the permeability of rock and rock cleavage pressure value. The test results on the choice of design options often play a decisive role. Based on the engineering practice, the authors studied the drillhole high-pressure packer permeability test in the pumped storage hydro-plant's underground powerhouse, by the analysis of test results, this article offers a demonstration of the deformation of rock fracture witch under building in the condition of high-pressure water head, it provides a more detailed engineering geological background.展开更多
In liner cementing,the upper cement plug and inner components of a common hanger needs to be drilled out after cementing,which will result in a poor cementing quality or even gas leakage at the flare opening.Therefore...In liner cementing,the upper cement plug and inner components of a common hanger needs to be drilled out after cementing,which will result in a poor cementing quality or even gas leakage at the flare opening.Therefore,a new packer-type drilling-free liner hanger has been developed,and a hydraulic setting-control packer,a flexible drilling-free seal box,and an auxiliary bearing back-off mechanism that go with the line hanger have been designed at the same time.Specific operation procedures include:(1)run in the liner string to the designed depth,then fully circulate the drilling fluid,finally drop the ball.When the tripping ball gets into the seat,the pressure will go up to cut off the hanging control pin and set the hanger;(2)continue to hold the pressure and cut off the ball seat pin to form circulation;(3)trip in the drill pipe to exert pressure on the hanger,back off to release the hanger from the running tool;(4)lower the drill pipe plug upon the completion of cement in-jection,cut off the releasing control pin of hollow casing plug,and run down further to bump with the bumping assembly;(5)remove the cementing head and connect the kelly driver,hold pressure again,then slowly pull up the drill tools,exert hydraulic pressure on the setting hydraulic cylinder of the packer assembly to cut off the setting control pin and set the packer;and(6)pull up the tools to the flare opening and wash out excessive cement slurry by circulating to realize free drilling of the whole hole.The successful application of the liner hanger in 127 mm diameter liner in Well BQ203-H1 indicates that the packer-type liner hanger has such advantages as easy hanging and back-off,accurate bumping,simple setting,and sound sealing performance.展开更多
基金financial support from the Fundamental Research Funds for the Central Universities under Grant nos. 17CX05020 and 17CX06002the Research Funds for Introducing Talent (PhD) of China University of Petroleum under Grant no. YJ20170026+1 种基金the National Science and Technology Major Project under Grant no. 2016ZX05042004the Joint Funds of the National Natural Science Foundation of China under Grant no. U1762104
文摘During hydraulic fracturing operations of low-permeability reservoirs,packers are the key component to ensure the success of multistage fracturing.Packers enable sections of the wellbore to be sealed off and separately fractured by hydraulic pressure,one at a time,while the remainder of the wellbore is not affected.However,reliable sealing properties of the packer rubber are required to meet the high-pressure and high-temperature(HPHT)conditions of reservoirs(such as 70 MPa and 170 ℃).In this study,the structures of the packer rubber with two different materials are optimized numerically by ABAQUS and validated by experiments.The optimization process starts from the packer rubber with a conventional structure,and then,the weakest spots are identified by ABAQUS and improved by slightly varying its structure.This process is iterative,and the final optimized structure of a single rubber barrel with expanding back-up rings is achieved.For the structure of three rubber barrels with metallic protective covers,both HNBR and AFLAS fail under HPHT conditions.For the final optimized structure,the packer rubber made of AFLAS can work better under HPHT than that made of HNBR which ruptures after setting.The results show that the optimized structure of a single rubber barrel with expanding back-up rings and the material AFLAS are a good combination for the packer rubber playing an excellent sealing performance in multistage fracturing in horizontal wells.
文摘Double packer equipment for hydraulic test can be used to measure pressure of test zone directly, and it is frequently used to perform many kinds of hydraulic tests and take groundwater sample from borehole. The test method of this equipment mainly includes the test design, implementation, interpretation and synthetic analysis. By adopting the double packer equipment for hydraulic test, the parameter distribution of rock permeability along borehole can be acquired, as well as the connectivity, water conductivity and water bearing capacity of the disclosed structure and the chemical characteristics of the deep groundwater. It is a necessary method for the research and evaluation of the complex hypotonicity terrace site selection under geological conditions. This method is not only suitable for the geological disposal of high level radioactive waste, but also can be used in the site selection of underground facilities such as storage of petroleum and carbon dioxide. Meanwhile, it has a good application prospect in other hydrogeological investigation fields.
文摘Usually the water head of the pumped storage hydro-plant is high, generally up to 400-500 m, therefore the rock mass under the high-pressure bifurcation pipe have to bear as high as millions Pascal water pressure, in according with the requirements of high water head pumped storage hydro-plant should be 1.2 times of the water head special high-pressure packer permeability test compared with normal to test the permeability of rock and rock cleavage pressure value. The test results on the choice of design options often play a decisive role. Based on the engineering practice, the authors studied the drillhole high-pressure packer permeability test in the pumped storage hydro-plant's underground powerhouse, by the analysis of test results, this article offers a demonstration of the deformation of rock fracture witch under building in the condition of high-pressure water head, it provides a more detailed engineering geological background.
基金2011 Overall Project of China National Petroleum Corpo-ration(No.2011T-0501).
文摘In liner cementing,the upper cement plug and inner components of a common hanger needs to be drilled out after cementing,which will result in a poor cementing quality or even gas leakage at the flare opening.Therefore,a new packer-type drilling-free liner hanger has been developed,and a hydraulic setting-control packer,a flexible drilling-free seal box,and an auxiliary bearing back-off mechanism that go with the line hanger have been designed at the same time.Specific operation procedures include:(1)run in the liner string to the designed depth,then fully circulate the drilling fluid,finally drop the ball.When the tripping ball gets into the seat,the pressure will go up to cut off the hanging control pin and set the hanger;(2)continue to hold the pressure and cut off the ball seat pin to form circulation;(3)trip in the drill pipe to exert pressure on the hanger,back off to release the hanger from the running tool;(4)lower the drill pipe plug upon the completion of cement in-jection,cut off the releasing control pin of hollow casing plug,and run down further to bump with the bumping assembly;(5)remove the cementing head and connect the kelly driver,hold pressure again,then slowly pull up the drill tools,exert hydraulic pressure on the setting hydraulic cylinder of the packer assembly to cut off the setting control pin and set the packer;and(6)pull up the tools to the flare opening and wash out excessive cement slurry by circulating to realize free drilling of the whole hole.The successful application of the liner hanger in 127 mm diameter liner in Well BQ203-H1 indicates that the packer-type liner hanger has such advantages as easy hanging and back-off,accurate bumping,simple setting,and sound sealing performance.
