长庆超低渗透油藏低产水平井重复改造技术研究及应用

发布时间：2018-12-19 21:09

【摘要】：受储层致密低压、完井改造程度低、长期注采驱替难以建立等因素影响,鄂尔多斯盆地部分水平井产量递减大而低产。通过对水平井典型注采井网的生产动态进行历史拟合,研究了油藏压力和剩余油分布特征。以扩大储层改造体积、增加裂缝复杂程度、恢复缝网导流、解除深部堵塞和提升地层能量为目的,集成体积压裂与补充能量为一体进行重复改造设计,形成了水平井"高排量注入、两级暂堵升压、多功能压裂液、压后关井扩压"的分段补能体积复压工艺模式和配套的压缩式双封单卡组合管柱。优化施工排量为4~6 m~3/min,缝口缝内两级暂堵转向,单段液量为800~1 000 m~3,单段压后关井1~2 d。在鄂尔多斯盆地超低渗透油藏开展了5口水平井现场试验,单井补能体积复压5~6段,井均日产油量由1.6 t提高至6.2 t,达到了本井投产初期产量,与同区块常规复压井相比日增油提高了1倍。井组地层能量上升2~4 MPa,1年累计增油量超过1 200 t,与本井初次压裂投产相比年递减率降低38%。该技术对其他非常规储层提高水平井老井产量及最终采出程度有一定的借鉴。
[Abstract]:Due to the tight and low pressure of reservoir, the low degree of well completion and the difficulty of establishing injection and production displacement for a long time, the production of some horizontal wells in Ordos Basin is decreased greatly and low. Through the historical fitting of production performance of typical injection-production pattern in horizontal wells, the distribution characteristics of reservoir pressure and remaining oil are studied. In order to enlarge the volume of reservoir reconstruction, increase the degree of fracture complexity, restore the diversion of fracture network, remove the deep blockage and raise formation energy, and integrate volume fracturing with supplementary energy to carry on the repeated reconstruction design, In horizontal well, the technology model of high displacement injection, two stage temporary plugging and boosting, multifunctional fracturing fluid and well closing and expanding after compression is formed, and the compressing double seal single card combined string is also formed. The optimal construction displacement is 4 ~ 6 m / min, the two stages of temporary plugging turn in the fracture joint, the single section liquid quantity is 800 ~ 1 000 m ~ (3), and the single section is closed for 1 ~ 2 d after pressing. Field tests of 5 horizontal wells were carried out in ultra-low permeability reservoirs in Ordos Basin. The average daily oil production increased from 1.6 t to 6.2 t, and the average daily oil production increased from 1.6 t to 6.2 t, which reached the initial production rate of this well. Compared with the conventional complex well in the same block, the daily oil increased by twice as much as that in the same block. The formation energy of the well group is increased by 2 ~ 4 MPa, a year, and the cumulative oil increment is more than 1 200 t, which reduces the annual decline rate by 38 times compared with the initial fracturing and production of the well. This technique can be used for reference to other unconventional reservoirs to improve the production rate and final recovery degree of horizontal wells.
【作者单位】：中国石油长庆油田分公司油气工艺研究院;低渗透油气田开发国家工程重点实验室;中国石油长庆油田分公司第十采油厂;
【基金】：国家科技重大专项“超低渗透油藏有效开采技术”(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)
【分类号】：TE357

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