孔雀区块水平井压裂产能优化设计与经济评价

Horizontal Well Fracturing Productivity Optimization and Economic Evaluation Study in Peacock Block

孔雀区块位于塔里木盆地北部坳陷东北部,该区块志留系砂岩储层物性极差,属于低孔低渗碎屑岩气藏,垂直井已经难以满足此类气藏的勘探开发需求;因此深入开展水平井分段压裂优化设计及经济评价研究具有重要意义。提出了统一压裂设计(UFD)方法,该方法基于最大化产能的目的,开发了一个叫做"支撑剂数"的参数,它把压裂规模与裂缝的最佳导流能力及最大生产指数相关联起来,在给定气藏地质特征条件下,以最优的生产指数为目标设计出最佳的裂缝几何形态。UFD方法的设计目标是最优的水力压裂设计,可产生一个最大的生产指数。同时在UFD物理产能最大优化的基础上与经济评价相结合,采用净现值(NPV)分析方法,分析最佳的水平井分段压裂施工方案。压裂优化实践表明孔雀井区水平段各种压裂方案均无法实现经济开发,多-短缝不适用于低孔低渗气藏的改造,需要寻找"甜点"进行有效开发。

Peacock block is located in the northeast of Tarim,which is Silurian clastic reservoir and its reservoir properties is poor.Currently it is unable to obtain the continuous production by vertical well fracturing,however well productivity has been improved greatly using staged fracturing technique in horizontal well.Therefore,the indepth research on optimal design of staged fracturing in the horizontal well has important significance.The method of UFD based on the purpose to maximize productivity is presented,in which a parameter called ＂ proppant number＂ is developed.With the parameter,the fracturing scale,and the best conductivity of crack and maximum production index are associated,then in a given gas reservoir geology condition the best production index for the target to design the optimal fracture geometry is taken.The goal of UFD is to get a maximum production index by hydraulic fracturing design.Through the fracturing optimization practice,in the Peacock block all kinds of fracturing schemes on horizontal section failed to achieve economic development have been found,and multi-short crack is not suitable for reforming the low porosity and low permeability gas reservoir,need to find a ＂ dessert＂ development.