A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible...A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible sidetracking tool to achieve low-cost sidetracking in the old wellbore,and then uses the hydraulic jet technology to induce multiple fractures to fracture.Finally,the bullhead fracturing of multi-cluster temporary plugging for the sidetracking hole is carried out by running the tubing string,to realize the efficient development of the remaining reserves among the wells.The flexible sidetracking stimulation technology involves flexible sidetracking horizontal wells drilling and sidetracking horizontal well fracturing.The flexible sidetracking horizontal well drilling includes three aspects:flexible drill pipe structure and material optimization,drilling technology,and sealed coring tool.The sidetracking horizontal well fracturing includes two aspects:fracturing scheme optimization,fracturing tools and implementation process optimization.The technology has been conducted several rounds of field tests in the Ansai Oilfield of Changqing,China.The results show that by changing well type and reducing row spacing of oil and water wells,the pressure displacement system can be well established to achieve effective pressure transmission and to achieve the purpose of increasing liquid production in low-yield and low-efficiency wells.It is verified that the flexible sidetracking stimulation technology can provide favorable support for accurately developing remaining reserves in low-permeability reservoirs.展开更多
Currently,unconventional reservoirs are characterized by low single well-controlled reserves,high initial production but fast production decline.This paper sorts out the problems of energy dispersion and limited lengt...Currently,unconventional reservoirs are characterized by low single well-controlled reserves,high initial production but fast production decline.This paper sorts out the problems of energy dispersion and limited length and height of main hydraulic fractures induced in staged multi-cluster fracturing,and proposes an innovative concept of“energy-focused fracturing development”.The technical connotation,theoretical model,and core techniques of energy-focused fracturing development are systematically examined,and the implementation path of this technology is determined.The energy-focused fracturing development technology incorporates the techniques such as geology-engineering integrated design,perforation optimization design,fracturing process design,and drainage engineering control.It transforms the numerous,short and dense hydraulic fractures to limited,long and sparse fractures.It focuses on fracturing energy,and aims to improve the fracture length,height and lateral width,and the proppant long-distance transportation capacity,thus enhancing the single well-controlled reserves and development effect.The energy-focused fracturing development technology has been successfully applied in the carbonate reservoirs in buried hill,shallow coalbed methane reservoirs,and coal-rock gas reservoirs in China,demonstrating the technology's promising application.It is concluded that the energy-focused fracturing development technology can significantly increase the single well production and estimated ultimate recovery(EUR),and will be helpful for efficiently developing low-permeability,unconventional and low-grade resources in China.展开更多
基金Supported by the National Key Research and Development Program of China(2023YFF0615403)CNPC Science and Technology Project(2023ZZ0803).
文摘A flexible sidetracking stimulation technology of horizontal wells is formed to develop the lateral deep remaining oil and gas resources of the low-permeability mature oilfields.This technology first uses the flexible sidetracking tool to achieve low-cost sidetracking in the old wellbore,and then uses the hydraulic jet technology to induce multiple fractures to fracture.Finally,the bullhead fracturing of multi-cluster temporary plugging for the sidetracking hole is carried out by running the tubing string,to realize the efficient development of the remaining reserves among the wells.The flexible sidetracking stimulation technology involves flexible sidetracking horizontal wells drilling and sidetracking horizontal well fracturing.The flexible sidetracking horizontal well drilling includes three aspects:flexible drill pipe structure and material optimization,drilling technology,and sealed coring tool.The sidetracking horizontal well fracturing includes two aspects:fracturing scheme optimization,fracturing tools and implementation process optimization.The technology has been conducted several rounds of field tests in the Ansai Oilfield of Changqing,China.The results show that by changing well type and reducing row spacing of oil and water wells,the pressure displacement system can be well established to achieve effective pressure transmission and to achieve the purpose of increasing liquid production in low-yield and low-efficiency wells.It is verified that the flexible sidetracking stimulation technology can provide favorable support for accurately developing remaining reserves in low-permeability reservoirs.
基金Supported by the PetroChina Scentific and Technological Projects(2023ZZ082023ZZ28)。
文摘Currently,unconventional reservoirs are characterized by low single well-controlled reserves,high initial production but fast production decline.This paper sorts out the problems of energy dispersion and limited length and height of main hydraulic fractures induced in staged multi-cluster fracturing,and proposes an innovative concept of“energy-focused fracturing development”.The technical connotation,theoretical model,and core techniques of energy-focused fracturing development are systematically examined,and the implementation path of this technology is determined.The energy-focused fracturing development technology incorporates the techniques such as geology-engineering integrated design,perforation optimization design,fracturing process design,and drainage engineering control.It transforms the numerous,short and dense hydraulic fractures to limited,long and sparse fractures.It focuses on fracturing energy,and aims to improve the fracture length,height and lateral width,and the proppant long-distance transportation capacity,thus enhancing the single well-controlled reserves and development effect.The energy-focused fracturing development technology has been successfully applied in the carbonate reservoirs in buried hill,shallow coalbed methane reservoirs,and coal-rock gas reservoirs in China,demonstrating the technology's promising application.It is concluded that the energy-focused fracturing development technology can significantly increase the single well production and estimated ultimate recovery(EUR),and will be helpful for efficiently developing low-permeability,unconventional and low-grade resources in China.
