荆丘地区双层组合套管的钻井液工艺

DRILLING FLUID TECHNIQUE IN THE WELLS OF DUAL CASINGS IN JINGQIU AREA

荆丘地区为了防止2750～3000m膏盐地层塑性蠕动挤毁套管，采用了双层组合套管新工艺。根据地层岩性和双层组合套管施工的特点，要求钻井液防卡、防塌及抗电介质污染。为此选用了PAC141－NPAN—SMP聚合物防塌钻井液体系。钻进中用液体润滑剂，完井时用固体润滑剂塑料小球；防塌剂用SBI—1。施工13口井，均未发生过压差卡钻；除2口井在上部地层因未灌浆井塌外，其它都未发生过井塌；一次电测成功率达84．6％；对油层还有保护作用。与32口井深相当的对比井相比，一次电测成功率提高31．5个百分点，处理复杂情况和事故时间减少9．6个百分点，钻井周期缩短35．47％，建井周期缩短28．44％。

This paper introduced the mud technique in dual casing well in Jingqiu area of North China oil field. The dual casings have been adopted to prevent casing from collapsing by creeping formation with plastic salt lime. The formations and dual casing technology require mud has the properties with anti-sticking, stabilization of borehole and anti-pollution of electrolyte. For the purpose,PAC141 -NPAN -SMP polymer mud systems were selected.