巴48-5井区保护油层钻井液技术  

Reservoir protection drilling fluid technology for Ba48-5 wellbock.

作　　者：汪桂娟[1,2] 贾东民[2] 左凤江[2] 刘德庆[2] 田野[2] 孙东山[2] 薛莉[2] 刘萍[2] 

机构地区：[1]西安石油大学石油天然气工程学院 [2]华北石油管理局钻井工艺研究院

出　　处：《钻井液与完井液》2005年第3期70-71,共2页Drilling Fluid & Completion Fluid

摘　　要：巴48-5井区储层物性与邻近区块存在差异,而且压力异常,压力系数为0.38-1.01,属于低压裂缝性砾岩储层,先期完钻的巴48-5、巴48-46等井储层受到了严重污染。室内通过应用超低渗透钻井液技术中提出的砂床评价方法来评价油层保护剂的封堵效果,研制出了适用于巴48-5井区的油层保护剂RP-5。该剂的特点是:颗粒的粒度分布范围较宽(2.00-300μm),以较大尺寸材料为主,保证钻井液中有足够多的架桥粒子;采用了纤维状、片状、颗粒状等不同类型的惰性材料;引入了特殊聚合物材料,它在形成泥饼时吸附粘结不同的封堵材料和钻井液中的固相颗粒,从而增强封堵层的致密度和强度。室内评价结果表明,该油层保护剂对现场井浆性能无不良影响,能有效降低钻井液的砂床滤失量,提高封堵效率。该油层保护剂先后在巴48-39等6口井中进行了现场应用,其中巴48-39井表皮系数为0.21,巴48-31井表皮系数为-1.56,可以看出应用井的油层保护效果获得了明显提高。Ba48-5 wellbolck has physical characteristics different from that of the adjacent blocks. Its pressure is'abnormal, with the pressure coefficient of 0. 38-1. 01, which classifying it as low pressure-fractured gravel formation. From data from the drilled wells of Ba48-5 and Ba48-46, we can see the reservoir formation was severely polluted. Using sand bed filtration test proposed in ultra-low filtration drilling fluid technique, a reservoir protecting agent RP-5 was studied and evaluated on its sealing effect. The characteristics of this agent includes; 1) The particles'size distributes in 2. 00-300 μm, in which most are large solids, providing enough bridging particles in drilling fluid; 2) Inert materials of fiber, sheet and grain in shape were employed; 3) Particular polymer material was introduced to link different sealing particles'in drilling fluid to improve the tightness and strength of the plugging zone. Lab evaluation result's showed RP-5 plays no role in on-site drilling fluid. It effectively reduced the sand bed filtrate and increases the sealing efficiency. This agent was used in 6 wells, the skin coefficient of Ba48-39 was 0. 21, and that of Ba48-31 well was-1. 56, illustrating the improvement in reservoir protection by using RP-5.

关 键 词：防止地层损害 油层封堵 钾铵基聚合物钻井液 油层保护剂 裂缝性油藏 二连油田 

分 类 号：TE254.4[石油与天然气工程—油气井工程] TE258