低孔低渗储层完井改造一体化工作液的研究与应用

Study and Application of A Composite Well Completion and Stimulation Fluid for Low Porosity and Low Permeability Reservoirs

针对海上M油田储层段低孔低渗的特点,如果使用常规完井液,仅仅起到完井的作用,不能对储层进行改造达到提高产能的目的。通过大量室内实验,优选出了适合低孔低渗储层的降压助排剂HWDA-2、溶蚀剂HTA-H、缓蚀剂HCA101-8以及防乳破乳剂H409。最终研究出1套适合该油田低孔低渗储层的完井改造一体化工作液体系,在完井的同时,其对储层也具有一定的改造能力。性能评价结果表明,体系具有良好的防膨性,平均防膨率为96.4%,较低的腐蚀性以及较好的储层改造能力,岩心驱替渗透率恢复值可以达到120%以上。现场2口井的应用情况表明,使用完井改造一体化工作液的油井比使用常规隐形酸完井液时具有较低的表皮系数、较高的比采油指数,并且初期产油量增加30%以上,具有比较明显的增产效果。

Wells drilled in the offshore low porosity low permeability M oilfeld are completed with conventional completion fuidsthatlack the ability to stimulate the reservoirs. A composite well completion and stimulation fuid has recently been formulated with some optimized additives suitable for use in low porosity low permeability reservoirs, such as a clean-up additive HWDA-2, a corrosion solvent HTA-H, a corrosion inhibitor HCA101-8, and a demulsifer （with emulsifcation prevention ability） H409. This fuid is both a well completion fuid and a stimulation fuid. In laboratory experiments, the fuid showed percent reduction of core swelling of 96.4% and percent permeability recovery of 120%, indicating that the fuid had good inhibitive capacity and low corrosion. Application of the fuid on two wells acquired lower skin factor and higher specifc productivity index compared with other wells completed with conventional latent acid completion fuids. Early-stage oil production was increased by about 30%, indicating that the fuid had good stimulation capacity.