裂缝型致密砂岩油藏缝网压裂技术试验

Test of network fracturing in fractured tight sandstone reservoir

缝网压裂技术是非常规油气藏改造的关键技术之一。泾河油田属于裂缝型致密砂岩油藏,为了实现水平井的高效开发,提高油藏的最终采收率,分析了缝网压裂工艺在该油田裂缝型致密砂岩油藏中的适用条件,认为储层天然裂缝发育,脆性特征指数在38.4%-42.4%,水平应力差异系数小,净压力大于水平最大、最小主应力之差,满足实现缝网压裂的必要条件。在此基础上,优化了压裂液、支撑剂及施工参数,并在JH69P25井进行了试验,净压力分析表明压后形成了复杂的缝网系统,日产油2.55 t,取得了较好的改造效果。

Seam network fracturing technology is one of the key technologies for unconventional reservoir transformation.Jinghe Oilfield belongs to fractured tight sandstone reservoirs.In order to achieve efficient development of horizontal wells and improve ultimate recovery,suitable conditions of seam network fracturing technology for fractured tight sandstone reservoirs were analyzed.It is considered that reservoirs with natural fissure developed,brittleness index within 38.4% ￣42.4%,small horizontal stress difference coefficient,and net pressure greater than the difference between maximum and minimum horizontal stresses are the necessary conditions.Parameters for fracture fluid,proppant,and implement were optimized,which was applied to Well JH69P25.Net pressure fitting shows the network fractures were formed with output 2.55 t per day.