高平4水平井组双保钻井液技术

高平4井组水平井主要用于开发安塞长10组油藏。针对该井组上部直罗组和富县组易坍塌、下部地层钻速相对较慢、地层易造浆的特点，研究应用了环保型聚硅酸盐-黄胞胶钻井液体系。该体系具有抑制性强、润滑和剪切稀释性好的特点，有利于安全快速钻井，对环境污染极小。通过小型配浆实验确定钻井液施工方案，中测后稀释钻井液，降低钻井液滤失量和密度，加强固相控制，使用保护油层的酸溶性暂堵剂和降滤失剂，可最大限度地保护油层。

Technology of environmental protetive and formation protective drilling fluid for Gaoping 4 horizontal well group

Gaoping 4 horizontal well group are mainly used to develop the reservoir of Chang 10 reservoirs in Ansai oil field. Environmental protective drilling fluid prepared mainly with poly-silicate and xanthan gum is developed in accordance with such distinguishing features as the collapse of Zhiluo and Fuxian faults in upper strata, low drilling rate in the lower strata, and high mud making property of formation. The drilling fluid is beneficial to safe and smart drilling and has less environmental pollution because of its advantages of high inhibition, lubrication and shear thinning behavior. The working project of drilling fluid is determined by the pilot mud lab test. The drilling fluid is diluted after drill-stem testing. And then, the filtrate volume and density are also reduced. Based on the strong solid control and the application of formation protective acid-soluble bridge-plugging agent and filtrate reducer, the reservoir has been protected to the most extent.