华北油田复杂井固井技术

针对华北油田二连阿南，哈南高压注水采油区块和冀中潜山深井区块固井难度大和固井质量差等问题。华北石油管理局钻井工艺研究院在二连地区采用早强，膨胀和低失水水泥浆，并配合使用套管外封隔器，两凝固井工艺技术。解决了低温高压注水调整井固井作业中存在的问题，提高了固井质量；在冀中地区采用低密度，高强度，零析水，成膜型降失水水泥浆，配合采用双压双凝固井工艺技术，有效防止了井漏，油水互窜等井水复杂事故，提高了固井质量。早强，膨胀和低失水水泥浆低温早强，失水量小于200mL，在凝结过程中能产生有效膨胀，初凝和终凝时间较短，能有效防止气窜及油水互窜，成膜型降失水水泥浆失水量小于100mL，密度和稠化时间易调；有机塑性高分子胶粒在水泥凝结过程中由于被压缩而微膨胀，能有效补偿水泥石孔隙压力，达到防窜，改善水泥石韧性和变形能力的目的。

Cementing technology for complex wells in Huabei Oilfield

The complex wells of Huabei oilfield are mainly distributed in A'nan and Ha'nan HP water flood recovery blocks in Erlian block and buried hill deep well blocks in Jizhong, and cementing operating and cementing quality in the blocks are difficulty and poor. Therefore, pertinent practices have been done in Drilling Tech. Research Inst. of Huabei Petroleum Administration. Many problems existed in adjustment wells cementing operating on LTHP in Erlian block were solved effectively by u-sing early strength, expanding and less fluid loss cement slurry system with external casing packer and separable setting cementing techniques, and outflow of fluid in HP formation was controlled ultimately and cementing quality was improved. Circulation loss, oil-water channeling and other downhole troubles happened in Jizhong blocks were prevented by using low density, strong strength, zero free water, film-forming-type fluid loss cement slurry system with bi-pressure and separable setting cementing techniques, and cementing quality was enhanced massively. The research showed early strength, expanding and less fluid loss cement slurry system has the following characteristics: early strength on low temperature, fluid loss less than 200 mL, effectively expanding during setting, short initial and final setting times, preventing gas channeling and oil-water channeling; film-forming-type fluid loss cement slurry system has such performances as API fluid loss less than 100 mL, adjusting density and thickening time easily, organic plastic macromole gel particles slightlyswelling for being compressed during cement setting, which can effectively compensate the pore pressure of cement, a-void oil-water channeling, and improve toughness and def ormability of cement stone, short initial and final setting times.