基于渗透率分级的气藏水平井压裂方式

HORIZONTAL WELL FRACTURED MODES IN THE GAS RESERVOIRS BASED ON THE PERMEABILITY GRADINGS

水平井压裂是低渗油气藏特别是非常规天然气资源开发的重要技术,包括常规分段、细分切割和缝网压裂3种典型的分段压裂方式。利用数值模拟方法,以渗透率为量化指标,建立了基于渗透率分级的气藏水平井压裂方式优选准则。结果表明:在等施工规模和等控制面积两种情况下,缝网压裂相对于常规分段和细分切割压裂均具有优势,但随着渗透率的增加优势逐渐减弱;缝网压裂可划分为绝对优势、相对优势和不明显优势3种区域,绝对优势区内的气藏适合缝网压裂;等施工规模的常规分段压裂产生的裂缝较长,与细分切割压裂相比,能够更好地满足低渗储层对裂缝长度的需求。

Horizontal well fracturing is the important technique to develop low-permeability oil-gas reservoirs,especially the unconventional gas resources,including the following three typical segmentation fracturing forms: conventional,fine staged and fracture network ones. With the help of the numerical simulation,taking the permeability as the quantitative index,the optimizing standard of the horizontal well fracturing methods in the gas reservoirs is established on the basis of the permeability gradings. The achievements show that under the conditions of equal fractured scale and equal controlled area,the latter is advantageous than the former two,but with the rise of the permeability,the preference is decreased gradually; and moreover the advantage of the latter-fracture network fracturing can be further subdivided into absolute,relative and inconspicuous ones. The gas reservoir with the absolute advantage is suitable to be produced by the fracture network fracturing; the induced fractures by the conventional staged fracturing with the equal operation scale are generally pretty longer,comparing with the fine segmentation fracturing,it can much better meet the requirements of the fracture length for the low-permeability reservoirs.