CAJ | 학술논문

基于对三维空间下水力裂缝尖端应力场以及作用在天然裂缝面上的应力场的分析，建立了水力裂缝穿透天然裂缝的判别准则。利用大尺寸真三轴水力压裂实验模拟系统，实验研究了不同产状天然裂缝、地应力对水力裂缝扩展行为的影响。实验研究表明：水力裂缝穿透预制裂缝的现象主要发生在高逼近角、高走向角、高水平应力差异系数、高水平应力差的区域；水平应力差存在一个临界值，大于该值，水力裂缝才可能穿透预制裂缝。实验结果与本准则预测结果吻合良好。应用本准则，预测四川盆地龙马溪组页岩气试验井水力裂缝不能穿透天然裂缝面，与微地震压裂监测解释结果一致。图8表1参15
기우대삼유공간하수력렬봉첨단응력장이급작용재천연렬봉면상적응력장적분석，건립료수력렬봉천투천연렬봉적판별준칙。이용대척촌진삼축수력압렬실험모의계통，실험연구료불동산상천연렬봉、지응력대수력렬봉확전행위적영향。실험연구표명：수력렬봉천투예제렬봉적현상주요발생재고핍근각、고주향각、고수평응력차이계수、고수평응력차적구역；수평응력차존재일개림계치，대우해치，수력렬봉재가능천투예제렬봉。실험결과여본준칙예측결과문합량호。응용본준칙，예측사천분지룡마계조혈암기시험정수력렬봉불능천투천연렬봉면，여미지진압렬감측해석결과일치。도8표1삼15
Based on the analysis of the stress fields near the hydraulic fracture tip and on the natural fracture surface, a criterion for identifying hydraulic fractures crossing natural fractures was proposed. A series of hydraulic fracturing tests were conducted to investigate the influences of natural fractures occurrence and horizontal stress contrast on hydraulic fracture propagation using large scale tri-axial fracturing system. The experiment results showed that the crossing happens in the region with high approaching angle and strike angle, large horizontal stresses and horizontal stress difference coefficient. Horizontal stress contrast has a critical value, only when it is above the critical value, may the hydraulic fracture cross the natural fracture. These experimental results agree with the predictions of this criterion well. It is predicted by this criterion that the hydraulic fracture of a test well in the Longmaxi shale formation, Sichuan Basin, can’t cross the natural fracture, which agrees with the micro-seismic monitoring results.