莺歌海盆地高温高压气田完井技术

Completion Technologies for HTHP Gas Fields in the Yinggehai Basin

南海莺歌海盆地F气田为高温高压气田,其高温、高压、高含CO2的特点造成井筒的完整性难以保障。为此,根据储层特点,选择了合理的完井方式;依据安全性与经济性兼顾的原则,选择了改良13Cr材质的油套管;根据气田的特点及开发要求,设计了不同井型的生产管柱及射孔管柱,选择了合适的井口采油树及井下工具,并研制了新型环空保护液,最终形成了适用于海上高温高压高含酸性气体气田开发的完井技术。F气田10余口井应用了该技术,生产过程中未出现环空带压现象。实践表明,该完井技术能有效降低井筒带压风险,为规模开发莺歌海盆地高温高压气田提供技术支持。

The F Gas Field in Yinggehai Basin of the South China Sea is an HTHP gas field,characteristics of high temperature,high pressure and high CO2 content has been the challenge to the integrity of wellbore,so the completion method was selected pertinently according to the characteristics of reservoirs.Based on the principle of keeping both the safety and the economy,the tubing/casing has been made by modified 13Cr material,and designed the different types of production strings.In terms of the characteristics of gas field and the development requirements,the selection of wellhead Christmas trees and downhole tools was carried out properly,the perforation pipe string was designed,and the proper annulus protection fluid was developed.In the end,it formed a completion technology suitable for the development of HTHP offshore gas fields with high acidic gas content.This completion technology has been applied in more than 10 wells of this gas field,and no sustained annulus pressure was observed during the production process,which indicated that the developed completion technology could effectively ensure the wellbore integrity of such gas fields,and provide supports for the large-scale development of HTHP gas fields in the Yinggehai Basin.