超低渗透油藏五点井网水平井无阻重复压裂技术研究与应用  

RESEARCH AND APPLICATION OF OPEN-FLOW REFRACTURING TECHNIQUE IN FIVE-SPOT HORIZONTAL WELLS OF THE ULTRA-LOW PERMEABILITY RESERVOIR IN THE ORDOS BASIN

作　　者：白晓虎[1] 陆红军[1] 庞鹏[1] 达引朋[1] 黄婷[1] 苏良银 

机构地区：[1]中国石油长庆油田分公司

出　　处：《钻采工艺》2016年第3期57-59,73,共4页Drilling & Production Technology

基　　金：国家重大科技专项"超低渗透油藏有效开采技术"(2011ZX05013-004);中石油科技项目"油气藏储层改造技术持续攻关专项"(2015CGCGZ004)

摘　　要：五点水平井注采井网+分段压裂开发有效提高了鄂尔多斯盆地超低渗透油藏初期单井产量,但受裂缝间距大、改造规模小、水平段中部能量补充困难等因素影响,长期生产产量递减较大。文中基于五点井网剩余油和压力场分布规律,以缩短地层流体渗流距离、减小渗流阻力小为目的,从增加储层改造体积、裂缝与油藏接触面积、复杂缝网导流能力和区域地层能量水平四个方面出发,形成了水平井"中高排量注入、近井筒+裂缝远端二级暂堵、组合粒径支撑剂、多功能压裂液、压后关井扩压"的分段重复压裂模式,优化施工排量为5~6 m^3/min,近井筒缝口4~6 mm暂堵剂一级封堵、裂缝端部2~3 mm暂堵剂二级桥堵来提高净压力,单井液量为5 000~6 000 m^3,分段压后关井扩压1~1.5 d。该技术在华庆长6超低渗透油藏现场应用后取得较好的增产效果,4口试验井与常规重复压裂相比,提高单井产量50%~70%,对其他油田的非常规储层提高老井单井产量有一定的借鉴意义。The ultra low-permeability reservoir in Ordos basin has three typical characteristics such as low permeability,low pressure and low abundance. The initial oil production of single well has been improved effectively by five-spot flood system and staged fracturing in recent years. However,with longterm producing,the horizontal well production decreased greatly because of large fractures' spacing,small stimulating scale and low reservoir pressure in the middle of the horizontal well without energy supplement. Based on the pressure distribution and remaining oil saturation distribution laws of five spot pattern,the open-flow refracturing technique was formed by shortening fluid seepage distance and decreasing filtrational resistance,increasing reservoir stimulating volume,reservoir contact area,fracture network conductivity and reservoir pressure. The refracturing technique used low viscosity fracturing fluid,middle-high pump rate,twice temporary plugging at near wellbore and fracture tip,combination particle size proppant,multi-functional fracturing fluid and shutting well to diffusion pressure after fracturing etc.to optimize the fracturing effect. The optimized results showed that the pump rate should be 5 ~ 6 m^3/ min,the first plugging on temporary plugging agent at wellbore should be 4 ~ 6mm,second at fracture tip should be 2 ~ 3 mm,single well fluid volume should be 4000 ~ 5000 m^3,per well shutting time should be 1~ 1. 5 days. This refracturing technique was applied in four testing horizontal wells in Huaqing ultra-low permeability oilfield in Ordos Basin. The per-well production increased about 50% ~70% compared with the production of other conventional refracturing horizontal wells. The technology has a certain significance for the development of other unconventional reservoirs.

关 键 词：超低渗油藏 水平井 五点井网 无阻重复压裂 优化设计 

分 类 号：TE357[石油与天然气工程—油气田开发工程]