双作用防气窜固井水泥浆体系的研究与应用

Double action gas block well cementation milk system

目前,固井界使用的防气窜水泥浆体系主要有3种:高气阻、缓失重和微膨胀体系。这些水泥浆体系的防气窜作用单一,不能从根本上解决高温超压气井、长裸眼易漏井的防气窜问题。利用水泥浆气侵阻力评价仪测试了常用水泥浆体系的气阻能力,通过对水泥浆的气阻能力、延缓失重能力和体积膨胀能力的综合评价,研制开发出了适合大环空固井和小间隙短裸眼固井的"高气阻微膨胀"双作用防气窜水泥浆体系,适合小间隙长裸眼固井的"高气阻缓失重"双作用防气窜水泥浆体系。2套水泥浆体系在南海西部海域十多口的高危气窜井应用,固井质量优良,可进一步推广应用。

At present,there are three different kinds of gas block well cementation milk systems:High air resistance,slow weightlessness,and micro-dilatancy systems.Because of its limit of single gas-block function,they cannot solve the gas breakthrough problem occurred in high temperature and surpressure gas wells as well as in long open leaky holes thoroughly.Air resistance capability of common cement milk systems were tested with gas cut drag appraisal meter.Two 'high gas resistance and slow weightlessness' double action gas block well cementation milk systems were developed by comprehensively evaluating the gas resistance,weightlessness delay and volume expansion abilities.The systems were suitable for big annular cementation and little gapping and shot open holes.They were used in more than 10 gassed out wells of high danger in western South China Sea zone,and the cement job quality is quite fine.The system should be further popularized and applied.