论文部分内容阅读
钻井液对低渗砂岩气藏的伤害主要来自钻井液滤液,滤液产生的伤害主要为水锁,同时也有水敏膨胀及高分子聚合物在孔隙内壁的吸附滞留作用以及少量的固相微粒进入形成堵塞,导致产量降低。针对这一问题,主要从改变储层表面性质着手,研制出了洗井液NDF-1。该洗井液使低渗砂岩气藏由强亲水变为弱亲水,消除储层毛细管压力,溶解进入的部分固相,拆散堵塞,从而提高气驱水效率。室内实验表明,洗井液NDF-1可以使现场DIF伤害后岩心渗透率恢复率得到明显提高,平均恢复率提高率达到133.45%。在CB3-3井进行了现场试验,通过试气结果表明,单井产量提高率达到35.71%。
The harm of drilling fluid to low-permeability sandstone gas reservoirs mainly comes from drilling fluid filtrate. The damage caused by the filtrate is mainly water lock, but also water-sensitive swelling and adsorption and retention of macromolecule polymer on pore wall and the formation of small amount of solid particles Blockage, leading to reduced production. In response to this problem, mainly from the change of the surface properties of the reservoir, developed a wash fluid NDF-1. The well flushing fluid makes the low-permeability sandstone gas reservoir change from strong hydrophilic to weak hydrophilic, eliminates the capillary pressure in the reservoir, dissolves part of the solid phase entering, and unblocks the blockage, thus improving the efficiency of gas-driven water flushing. Laboratory experiments show that NDF-1 can significantly improve the core permeability recovery after DIF injury, and the average recovery rate is 133.45%. A field test was conducted in CB3-3 well. The result of gas test showed that the single-well production increase rate reached 35.71%.