塔里木油田“三高”致密砂岩气藏防/解水锁技术

Water lock prevention/removal technology used in the “three-high” tight sandstone gas reservoirs of the Tarim Oilfield

安志杰

AN Zhijie

辽河油田公司钻采工艺研究院

Drilling and Production Technology Research Institute, PetroChina Liaohe Oilfield Company, Panjin 124010, Liaoning, China

针对影响塔里木油田高温、高盐、高压致密砂岩气藏开发效果的水锁效应，在现有技术的基础上筛选并复配了适用于该气藏的高效防/解水锁剂，配方为：0.1%改性烷基糖苷+0.02%氟碳表面活性剂+4%甲醇。利用致密砂岩气藏天然岩心，通过自吸实验、驱替实验和液相滞留实验，开展高效防/解水锁剂评价。实验结果表明：复配体系具有较好的吸附性和表面活性，处理后岩心自吸能力大幅度减弱，岩心含水饱和度降低了15%以上；随着驱替压力的升高，岩心渗透率增加；驱替压力为3.445 MPa时，处理前后岩心气测渗透率平均改善率在50%以上；在相同驱替压力下，与处理前相比，岩心的渗流能力增强，含水饱和度下降，大大减轻了岩心的水锁效应。该复配体系的研究，对恢复和提高致密砂岩气藏的产能，有一定的技术指导意义。

The development of the tight sandstone gas reservoirs of high temperature, high salinity and high pressure in the Tarim Oilfield is impacted by the water lock effect. In order to deal with this situation, the efficient water lock prevention/removal agent suitable for these gas reservoirs was screened and compounded on the basis of existing technologies. And its formula is 0.1% modified alkyl indicant +0.02% fluorocarbon surfactant +4% methanol. Then, imbibition experiment, displacement experiment and liquid retention experiment were carried out on the natural cores taken from tight sandstone gas reservoirs, so as to evaluate the efficient water lock prevention/removal agent. The experimental results show that the compounded system has better adsorptivity and surface activity. After the cores are treated, their imbibition capacity is reduced greatly and their water saturation is decreased by over 15%. With the increase of the displacement pressure, the core permeability increases. When the displacement pressure is as high as 3.445 MPa, the average improvement rate of the gas log permeability of the treated cores is over 50%. Under the same displacement pressure, the seepage capacity of the core is increased, the water saturation is decreased and the water lock effect is alleviated significantly after it is treated. The studies on this compounded system provide a certain technical guidance for the productivity recovery and improvement of tight sandstone gas reservoirs.

10.13639/j.odpt.2019.06.014