塔里木盆地顺9井区产能评价及提高产能技术

Productivity Evaluation and Technique for Enhancing Productivity in Wellblock Shun 9 of Tarim Basin

塔里木盆地顺9井区碎屑岩储层埋藏深,为特低孔、特低渗储层,岩性致密,渗透性极差,直井压裂投产后表现为供液不足、单井稳产能力差、产能低、采收率低、勘探开发成本高、经济效益相对较差;该井区通过水平井分段加砂压裂储层改造后,单井产能有明显提高。但常规压裂分段方案不能有效地优化产能与经济的关系,为此引进统一压裂设计(UFD)计算方法以有效地解决这个问题,通过油藏分析计算得出地层渗透率及地应力,运用P3D软件进行计算,得出无量纲裂缝导流能力CfD和无量纲生产指数JD;同时考虑不同改造规模下的生产能力,以最优生产指数为目标优化裂缝几何尺寸,要求针对最佳的裂缝几何尺寸进行优化压裂施工设计;在评价期内对产能进行预测,结合投入成本进行经济评价,与泵注程序相结合,最终得出设计优化结果。

The clastic reservoir in Wellblock Shun 9of Tarim Basin was buried deeply,it belonged to the reservoir with extra-low porosity and low permeability,its lithology was dense and permeability was very poor.The conventional vertical well perforating operation has been unable to get capacity.The fractures from acid fracturing formed preferable fluid channel,While can acquire a certain capacity,But the lesser of the area and radius of vertical well oil drain,And the poor permeability.Production after fracturing in straight wells presented that liquid supply was insufficient,the capacity of single well production stability was poor with low productivity and low oil recovery,production cost was high and economic efficiency was relatively low.Through reconstruction of staged sand fracturing in horizontal well,the capacity of single well increased obviously.The conventional staged fracturing program could not effectively optimize the relationship between productivity and economy,a method of unified fracturing design(UFD)was introduced to effectively solve the problem,formation permeability and in-situ stress obtained by reservoir analysis were calculated by using P3D software,the dimensionless fracture conductivity Cfd,Dimensionless production index JD were derived,at the same time,the production ability under different reconstructing scales was taken into consideration,the geometric size of fractures were optimized based on the optimal production index,and it was required that the optimal fracturing geometric size should be optimized,the productivity was predicted in the evaluation period.Economic evaluation is given in combination with production cost,and combined with pumping procedure,optimized result is obtained ultimately.