复杂地层条件下钻井液优化使用的探讨

中国石化西部新区等地层情况十分复杂,对在钻井中存在的钻井液问题进行了分析,着重从钻井液优化使用方面进行了探讨.认为:提高体系的抑制性,应该尽可能采用电性较高的钻井液,不同电性的处理剂尽量不要混用;为简化钻井现场配浆时间,提高钻井液流变性能及胶体稳定性,应按照钻井液配方,预先在泥浆站采用湿挤压钠化、改性和增效的方法制成方便钻井液复合粉;为在井壁形成高质量泥饼,钻井液体系应具备尽可能高的正电性,体系中固相颗粒应有一定的细度和合理级配,并且钻井过程中,井底应保持一定的过平衡压力,另外,应重视对所选用钻井液泥饼的物理化学性质进行检测和研究.

Discussion on drilling fluid's optimum usage in complex formation

In the new west area, formation lithology is complex. The problems related to the drilling fluids were analyzed and discussion was focused on drilling fluids optimum usage in complex formation. Several viewpoints were put forward: 1) To increase drilling fluid inhibitive ability, drilling fluid with high electric property should be used, and additives with opposite electricity should not be employed together. 2) To shorten the drilling fluid preparing time and improve the rheologieal behavior and the colloid stability of a drilling fluid, convenient mud compound powder should be prepared by sodium treatment, wetextrusion,modification and stimulation and: 3) To get high quality mudcake on the wall, the mud should has as high electric property as possible, the solid particle should have certain suitability and reasonable distribution,and certain over-balanced pressure should be kept downhole during the whole drilling process. In addition,inspection and research should be made on phy-chemical properties of mud cake produced by the drilling fluid used.