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针对塔里木油田超深裂缝性厚层改造效果不理想问题,分析确定了影响储层改造效果的主要因素及其影响规律,提出了储层高效改造对策。地质力学研究结果认为影响裂缝开启的因素主要有储层天然裂缝产状、储层地应力、改造时引起的孔隙压力增量、天然裂缝走向与最大主应力方向夹角、裂缝内聚力等。高角度天然裂缝容易发生剪切破坏开启;改造时孔隙压力增量越大、最大最小主地应力差越大,天然裂缝就越易剪切破坏开启;天然裂缝走向与最大主应力方向夹角越小,天然裂缝就越易剪切破坏开启;裂缝内聚力对裂缝开启率的影响较大,降低裂缝内聚力可大幅度增加裂缝开启率,裂缝内聚力从14MPa降低到0MPa,天然裂缝开启率从11.5%增加到71.2%,裂缝开启率增加59.7%。油藏数模研究表明提高储层纵向动用程度比提高储层横向动用程度更有利于提高单井产能。现场通过暂堵和大排量泵注提高井底压力,前置酸酸化降低裂缝内聚力,利于增加天然裂缝的开启率、加入可降解暂堵材料提高储层动用程度、改善增产改造效果,实现了储层高效改造的目的。
In view of the unsatisfactory effect of ultra-deep fractured thick-wall alteration in Tarim oilfield, the main factors that affect the effect of reservoir reform and their influence laws are analyzed and determined, and the countermeasures for high-efficiency reservoir reform are put forward. The results of geomechanics study suggest that the factors affecting the cracking are mainly the occurrence of natural fractures in reservoirs, the stress of reservoirs, the increment of pore pressure caused by the alteration, the angle between the direction of natural fractures and the direction of maximum principal stress and the cohesion of fractures. Natural fractures are more prone to shear failure to open; the larger the incremental pore pressure, the greater the maximum and minimum stress difference, the more natural fractures will be easier to shear and open; the more the angle between the natural fractures and the direction of maximum principal stress Small and natural cracks are more likely to be cut and broken. Crack cohesion has a greater influence on the cracking rate. Reducing the cohesion of cracks can greatly increase the cracking rate, reducing the cohesion of cracks from 14MPa to 0MPa and increasing the opening rate of natural cracks from 11.5% To 71.2%, crack opening rate increased 59.7%. Reservoir numerical modeling shows that increasing vertical utilization of reservoirs is more conducive to improving single-well productivity than increasing lateral utilization of reservoirs. Site by temporary plugging and large displacement pump to raise the bottom hole pressure, acid pre-front to reduce the cohesion of the cracks, which will help to increase the natural cracking rate, adding degradable temporary blocking material to improve reservoir utilization, improve the transformation effect of production and achieve The purpose of efficient reservoir reconstruction.