南海超高温高压气田开发钻完井技术可行性评估与关键技术研究

Technical feasibility evaluation and key technologies study of drilling and completion for development of UHTHP gas fields in South China Sea

南海莺琼盆地超高温高压区域存在"三超高、一极窄"的苛刻地质环境,气田开发钻完井技术面临巨大挑战。以L气田为例,依次从钻井极限、井身结构、控压钻井、完井工具等方面建立了超高温高压开发钻完井技术可行性评估思路,提出了开发井安全压力窗口预测、薄弱层预判与随钻前视、关键套管下深及井身结构优化、控压钻井技术适用性改造、主动提高地层承压能力、管材防腐与高密度无固相完井液协同、超高温高压完井工具分析等7项关键技术,并在L气田钻完井方案设计中取得良好应用成效。展望了超高温高压开发钻完井技术未来发展与研究趋势,以期为深海、深地及超高温高压油气勘探开发提供参考。

There is a harsh geological environment of"three ultra-highs and one ultra-narrow"in the ultra high temperature and high pressure(UHTHP)area of Yingqiong basin in South China Sea.Gas field development drilling and completion technologies are facing huge challenge.Taking the gas field L as an example,the feasibility evaluation idea of drilling and completion technology for UHTHP development is proposed successively from the aspects of drilling limit,hole structure,managed pressure drilling(MPD)and completion tools.This paper presents 7 countermeasures for development wells such as safe mud weight window prediction,weak layer prediction and looking ahead of the bit while drilling(IriSphere technology),key casing running depth and hole structure optimization,MPD applicability,active improvement of formation pressure bearing capacity,synergy of tubing corrosion prevention and high density solid free completion fluid,and UHTHP tolerant completion tools,which have been successfully applied in the drilling and completion program of the gas field L.The future development and study trend of drilling and completion technology for UHTHP development are extended in the paper so as to provide reference for exploration and development of deep-sea,deep burial and UHTHP oil and gas reservoirs.