准噶尔盆地东部致密油水平井钻井液技术研究

准噶尔东部致密油水平井局部非储层井段地层易水化膨胀、分散或剥落掉块,长水平段钻井液携砂和润滑减阻难度大。根据地质工程特征及钻井液技术难点,提出了针对性的钻井液技术对策。通过室内实验对现场常用降失水剂、抑制剂及封堵剂等关键处理剂的评价与优选,进一步简化了钻井液配方;并强化了钾钙基钻井液的抑制和封堵性能,形成了一套适用于准噶尔东部致密油长水平井的钻井液体系。结果表明,该钻井液具有较强的抗盐、抗钙及抗钻屑污染的能力,混油后的钻井液润滑性能可满足长水平段钻井延伸能力的要求,现场应用效果良好。

Drilling Fluid for Horizontal Well of Tight Oil Reservoir in Eastern Junggar Basin

Drilling in long horizontal section well of Tight Oil Reservoir in Eastern Junggar Basin puts forward higher requirements for drilling fluid technology. The horizontal well drilling in Jimsar tight oil reservoir of XinJiang oilfield has many difficulties, such as the long horizontal section, small borehole size, large annular pressure loss, low return velocity of drilling fluid and drilling with large friction resistance, etc. Many countermeasures of drilling fluids have proposed according to the difficulties encountered during drilling. The key agents, such as fluid loss agent, inhibiting agent, sealing agent, etc., have been evaluated through number of experiments, and the inhibitive and sealing properties have been strengthened. After adding white oil to the inhibitive drilling fluid system, the lubricating ability of drilling fluid can be improved significantly to meet the need of long horizontal selection requirement. The application results have shown that the drilling fluid have low fluid loss and stabile rheological properties.