CAJ | 학술논문

为了解水平井分段压裂过程中先压开裂缝诱导应力干扰下后续裂缝破裂点位置的影响因素及其影响规律，指导水平井分段压裂射孔位置的选择，推导建立了非等裂缝半长、非等间距和任意裂缝倾角的水力裂缝诱导应力干扰数学模型，在此基础上形成了破裂点计算数学模型。结果表明包括裂缝条数、长度和净压力在内的先压开裂缝参数以及原始主应力状态、水平井方位角和完井方式等都会影响后续裂缝破裂压力大小，从而影响破裂点的位置，其中原始地应力、已压开裂缝条数和长度以及完井方式对破裂点位置存在较大影响，水平井方位角和已压开裂缝净压力对破裂点位置影响较小；对于原始水平主应力差较小的砂岩储层，裂缝间干扰严重会导致应力发生反转，增大后续起裂裂缝破裂压力，导致施工困难，因此应该尽量避免裂缝间干扰；对于页岩储层，目前采用的分段多簇射孔技术，段间距定为60 m 左右破裂压力更低，更易于裂缝起裂。
위료해수평정분단압렬과정중선압개렬봉유도응력간우하후속렬봉파렬점위치적영향인소급기영향규률，지도수평정분단압렬사공위치적선택，추도건립료비등렬봉반장、비등간거화임의렬봉경각적수력렬봉유도응력간우수학모형，재차기출상형성료파렬점계산수학모형。결과표명포괄렬봉조수、장도화정압력재내적선압개렬봉삼수이급원시주응력상태、수평정방위각화완정방식등도회영향후속렬봉파렬압력대소，종이영향파렬점적위치，기중원시지응력、이압개렬봉조수화장도이급완정방식대파렬점위치존재교대영향，수평정방위각화이압개렬봉정압력대파렬점위치영향교소；대우원시수평주응력차교소적사암저층，렬봉간간우엄중회도치응력발생반전，증대후속기렬렬봉파렬압력，도치시공곤난，인차응해진량피면렬봉간간우；대우혈암저층，목전채용적분단다족사공기술，단간거정위60 m 좌우파렬압력경저，경역우렬봉기렬。
In order to understand the influencing factors for subsequent fracture breakdown point locations under the interference of induced stress by previously created fractures during staged fracturing in horizontal wells and their influencing law, and to guide the selection of perforation locations in staged fractured horizontal wells, the mathematical model for hydraulic fracture induced stress interference was built which had non-equal fracture half-length, non-equidistance and random fracture dip, and a mathematic model for calculation of breakdown point was established based on this. The results show that the previously created fracture parameters, including the number of fractures, their length and net pressure, and original dominant stress status azimuth of horizontal well and completion method can all affect the size of subsequent fracturing pressure, hence affecting the location of breakdown points. The original geostress, the number and length of previously created fractures and completion method pose a significant effect on the location of breakdown points, while the azimuth of horizontal well and net pressure of previously created fractures have little impact on the breakdown points. For sandstone reservoirs with small difference of original horizontal dominant stress, the severe interference between fractures may cause inversion of stress and increase the fracturing pressure of subsequently initiated fractures, causing difficulty in fracturing job. So the inter-fracture interference should be avoided as much as possible. For shale reservoirs, the staged multi-cluster perforation technique is used at present, and the fracturing pressure is even lower when the interval between stages is set at about 60 m, which helps fracture initiation.