Abstract:

Fracture height control is a key factor for the development of low permeability reservoir, especially for the thin and poor quality zones. Aiming at the challenges of poor capping rock and ample muddy interbedding of formation of block Lu44 in Huabei Oilfield, secondary sanding fracturing technology are conducted as a way of stimulation. The secondary sanding fracturing technology can make a contribution to fracture height control has been proved by using the fracture height migration model. Through FracproPT software, the fracture height is compared between secondary sanding fracturing and conventional fracturing. At the same time, based on the result of numerical simulation, the reasonable fracturing parameters, including second sand volume, second preflush ratio, pump off time and delivery rate, are optimized. The secondary sanding fracturing has a good adptability in Huabei Oilfeild and better production in other wells.

Key words: Secondary sanding fracturing, Thin and poor quality zone, Reasonable fracturing parameters, Fracture height control

摘要： 对于低渗透薄差层的改造,控制缝高是影响改造效果的关键因素。华北油田路44区块薄差层砂泥互层严重,上下隔层应力较弱,常规的加砂压裂工艺适应性较差,因此决定采用二次加砂压裂工艺。通过建立裂缝沿缝高扩展模型,论述了二次加砂压裂具有控制缝高的作用。并根据路44区块油井的地质参数和施工参数,利用FracproPT软件进行二次加砂压裂施工模拟,将其与常规加砂压裂对比,结果表明在加砂量相同的情况下,油井在二次加砂压裂后裂缝高度较小。最后结合数值模拟结果对加砂量、第二次注入前置液的比例、停泵时间和排量4个施工参数进行分析,确定出最佳的施工参数范围。研究对于油田现场二次加砂压裂的施工具有一定的指导意义,将研究结果应用于现场其他井中,增产效果较好。

关键词: 二次加砂, 薄差层, 参数分析, 控制缝高