石油钻采工艺2017，Vol.39Issue(4)：521-527,7.DOI:10.13639/j.odpt.2017.04.022
长庆超低渗透油藏低产水平井重复改造技术研究及应用
Study on repeated stimulation technology and its application to in low-yield horizontal wells in ultra low permeability oil reservoirs, Changqing Oilfield
摘要
Abstract
In the Ordos Basin, the production rate of some horizontal wells declines significantly to the low value for the reservoirs are tight with low pressure, the completed wells are less stimulated and long-term injection and production displacement cannot be established easily. In this paper, history match was performed on the production performance of typical injection-production pattern of horizontal well to investigate the oil reservoir pressure and remaining oil distribution characteristics. Volumetric fracturing and energy complement was integrated for repeated stimulation design so as to enlarge reservoir stimulation volume, increase fracture complexity, recover fracture network diversion, remove deep blockage and improve formation energy. Then, the technological model for the staged energy complement and repeated volumetric fracturing of horizontal well was established, i.e., "high flow rate injection, two-stage tem-porary plugging for boosting, multi-functional fracturing fluid, and post-fracturing shut in for diffusion", and its support compression string with twin packer and single slip was developed. The optimized flow rate is 4-6 m3/min, there is two-stage temporary plugging for diversion at the opening and inside of fracture, the fluid volume in each section is 800-1000 m3 and shut in period after fracturing of each section is 1-2 d. It was tested on site in 5 horizontal wells in ultra low permeability oil reservoirs in the Ordos Basin. Energy complement and repeated fracturing is carried out at 5-6 sections in each well, and average daily oil production of each well is increased from 1.6 t to 6.2 t, which is equal to its production rate at the early stage of commissioning. And its oil increment is 100％ higher than that of the wells which are treated with the conventional repeated fracturing in the same block. The formation energy of the well group rises by 2-4 MPa, the cumulative oil increment is over 1200 t one year, and yearly decline rate is 38％ lower than that after the initial fracturing of this well. This technology can be used as the reference for increasing the production rate and ultimate recovery factor of old horizontal wells in unconventional reservoirs.关键词
鄂尔多斯盆地/低渗透油藏/水平井/重复改造/体积压裂/补充地层能量/长庆油田Key words
Ordos Basin/low-permeability oil reservoir/horizontal well/repeated stimulation/volumetric fracturing/formation energy complement/Changqing Oilfield分类
能源科技引用本文复制引用
苏良银,白晓虎,陆红军,黄婷,吴华正,达引朋..长庆超低渗透油藏低产水平井重复改造技术研究及应用[J].石油钻采工艺,2017,39(4):521-527,7.基金项目
国家科技重大专项"超低渗透油藏有效开采技术"(编号:2011ZX05013-004) （编号:2011ZX05013-004）
中石油科技项目"油气藏储层改造技术持续攻关专项"(编号:2015CGCGZ004). （编号:2015CGCGZ004）
