渤海中部BZ34-2EW区块防塌钻井液试验研究

EXPERIMENTAL STUDY ON PREPARATION OF DRILLING FLUID FOR ROCK SAMPLE FROM BOHAI BZ34 2EW BLOCK

对ＢＺ３４２ＥＷ区块地层岩样进行了理化性能分析和电镜分析，结果表明，该区块属于层理、裂隙发育的易剥落坍塌的硬脆性页岩地层。无机盐几乎不能抑制岩样水化膨胀，而合适的钻井液可以抑制其水化膨胀，且具有较高的页岩回收率。加入硅酸钠的低粘土相海水聚合物钻井液体系的流变性能好，抑制能力强，泥饼质量好，可用于层理、裂隙发育的硬脆性页岩地层的钻进。

Rock samples of BZ34 2EW block at Bohai area were analyzed by means of physical chemistry and scanning electron microscope(SEM). The block features hard and brittle shale formation with fissile bedding and multiple fracture. Inorganic salts can hardly inhibit the hydration and expansion of rock sample, but some drilling fluids for inhibiting hydration and expansion of rock are proper. Laboratory test shows that the polymer seawater drilling fluids with sodium silicate and low clay content have good rheology and inhibility. This kind of drilling fluid is favorable for getting high recovery of shale and good cake, and can be used for drilling hard and brittle shale formation.