弱凝胶-BOSW钻井液在吐哈油田水平井的应用  

Application of Weak Gel BOSW Drilling Fluid in Horizontal Drilling in Tuha Oilfield

作　　者：马平平 付伟明 张荣志 王义虎 冯海平 全晓虎 

机构地区：[1]中国石油吐哈油田分公司工程技术研究院 [2]北京石大博诚科技有限公司

出　　处：《钻井液与完井液》2014年第3期24-27,96-97,共4页Drilling Fluid & Completion Fluid

摘　　要：吐哈油田三塘湖盆地泥岩中伊蒙混层的含量高,且伊蒙混层比也较高,泥岩易发生水化膨胀,导致井壁失稳,因此要求钻井液具备很强的抑制性,同时该区块水平井钻井施工中的钻井液悬浮携带能力也是一个难点。为解决以上问题,研究出了快速弱凝胶BC-VIS以及辅助提切剂BC-BPG,以他们为主剂,并通过选用BOSW超微加重剂,形成了适合吐哈油田水平段的弱凝胶钻井液体系。BC-VIS的成胶时间短,对成胶温度要求低,具有良好的抗温和抗盐性能;BC-BPG是一种正电胶产品,该产品不但具有良好的封堵效果,而且润滑效果良好,与BC-VIS配合使用能提高体系的动塑比,明显提高携岩效果;BOSW超微加重剂属于纳米和准纳米级粒子,具有良好的自我分散性和悬浮性。性能评价结果表明,该体系的抑制性、动塑比、储层保护性能均较好。该体系在马57H、马56-6H和马58H井进行了试验应用,取得良好效果,钻井过程中无复杂,固井顺利,表明该体系在水平钻进中具有良好的应用前景。In the Santanghu block of Tuha Oilfield, illite/smectite mixed layers are frequently found in the formations drilled. These mixed-layer formations are very easy to get hydrated and swelling when in contact with water, resulting in borehole sloughing. Rheology of drilling fluid in horizontal drilling is another requirement that needs attention because of hole cleaning and settling stability. A drilling fluid formulated with a weak gel agent and a viscosifier was developed for use in horizontal drilling in Tuha Oilfield. This weak gel drilling fluid have good inhibitive capacity, suspension capacity and reservoir compatibility. The performance of the drilling fluid is greatly improved when a ultra-fine weighting agent BOSW is used. This fluid has been used in Well Ma-57H,Well Ma56-6H and Well Ma58H, no downhole troubles have been encountered drilling, and cementing job was done without a hitch.

关 键 词：水平钻井 弱凝胶钻井液 弱凝胶剂 触变性 超微加重剂 

分 类 号：TE254.3[石油与天然气工程—油气井工程]