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
在塔里木油田测试作业中,出现诸如封隔器胶筒高温碳化失封、“O”密封圈气爆破损渗漏、高压差失封等问题,无法安全优质地完成超深超高压高温气井的测试需要。为提升井下测试工具耐温耐压性能,基于塔里木油田“十三五”以来超深高温高压...在塔里木油田测试作业中,出现诸如封隔器胶筒高温碳化失封、“O”密封圈气爆破损渗漏、高压差失封等问题,无法安全优质地完成超深超高压高温气井的测试需要。为提升井下测试工具耐温耐压性能,基于塔里木油田“十三五”以来超深高温高压井APR测试实践,总结分析了常规高温高压井测试APR测试工具存在的问题,通过提升密封部件材料的耐温等级、优化密封组合形式、改进封隔器胶筒结构等手段,将APR测试工具的耐温耐压差性能由70 MPa/177℃提升至105 MPa/204℃。经室内高温高压评价实验,封隔器设计等级、耐温耐压等关键指标满足设计要求。现场DB×井使用改进型193.675 mm CHAMP-Ⅳ封隔器、MJ×井使用改进型127 mm RTTS封隔器,作业期间井下工具工作正常,测试均取得成功,起出检查测试工具完好。改进的APR测试工具为超深高温高压井高质量勘探开发打下了坚实的基础。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.
文摘在塔里木油田测试作业中,出现诸如封隔器胶筒高温碳化失封、“O”密封圈气爆破损渗漏、高压差失封等问题,无法安全优质地完成超深超高压高温气井的测试需要。为提升井下测试工具耐温耐压性能,基于塔里木油田“十三五”以来超深高温高压井APR测试实践,总结分析了常规高温高压井测试APR测试工具存在的问题,通过提升密封部件材料的耐温等级、优化密封组合形式、改进封隔器胶筒结构等手段,将APR测试工具的耐温耐压差性能由70 MPa/177℃提升至105 MPa/204℃。经室内高温高压评价实验,封隔器设计等级、耐温耐压等关键指标满足设计要求。现场DB×井使用改进型193.675 mm CHAMP-Ⅳ封隔器、MJ×井使用改进型127 mm RTTS封隔器,作业期间井下工具工作正常,测试均取得成功,起出检查测试工具完好。改进的APR测试工具为超深高温高压井高质量勘探开发打下了坚实的基础。
