顺南井区优快钻井技术

Optimal and Fast Drilling Technology for Shunnan Block

顺南区块具有储层埋藏深、地层温度异常高等特点,钻井中易出现钻井液抗温性能不足、井壁失稳、发生井斜等问题,导致钻井周期长、钻井成本高,严重影响了该区块的勘探开发进程。为此,进行了优快钻井技术研究。首先,根据顺南区块的地质条件和三压力剖面,对井身结构进行了优化。其次,在分析井壁失稳原因的基础上,通过大量试验,优选了抗高温防塌钻井液配方。然后,针对却尔却克组地层钻进过程中易发生井斜的问题,采用成本低、控斜效果较好的"MWD+单弯螺杆"防斜打快技术。最后,为解决气层安全密度窗口窄、易发生井涌和井漏的问题,采用控压钻井技术钻进气层。现场应用表明,应用优快钻井技术后,提高了井身质量,缩短了钻井周期,实现了安全钻井。这表明,该优快钻井技术适用于顺南区块,可以解决该区块钻井中存在的问题,可为加快该区块的勘探开发进程提供技术支持。

Since the reservoirs are deep and geothermal temperature is abnormally high in Shunnan Block,some drilling problems are related to the deficiencies of drilling fluid performance;problems,such as the wellbore lost stability and the well was easily deviated and so on,caused long drilling time and high drilling cost,have seriously slowed down the progress of exploration and development of the block.Some studies on optimal and fast drilling techniques had been made to solve the problems mentioned above.Based on the geological conditions in Shunnan Block and curves of three formation pressures foreseen,the casing program design had been further optimized.On the basis of analysis of wellbore instability,through a lot of tests,new recipe of drilling fluid was selected to solve high temperature and wellbore sloughing problem.To cope with the problem of hole deviation in Queerquek Formation,BHA of MWD＋single bent PDM motor was used for drilling fast,which is cheap and has good function of anti-deviation.To overcome the problem that safe window for mud density adjustment is narrow in gas reservoir and gas kick or losses easily to happen,MPD technique was applied to drill gas reservoir zones.Field applications showed that fast drilling technique could improve the wellbore quality,shorten the drilling time and achieve a safe drilling.This indicated that fast drilling technique was applicable to Shunnan Block,could solve the existing problems of drilling and could provide technical support to the acceleration of exploration and development of the block.