四川盆地高温高压含硫气井五级分支井钻完井技术

MX023-H1井是四川盆地龙王庙组气藏的一口五级分支井，目的是为验证分支井技术在深层碳酸盐岩气藏高效开发的适应性。该井作为国内第一口高温高压含硫五级分支气井，分支井眼钻完井作业面临完井级别高、作业程序多、井身质量要求严格、复杂套管串下入难度大、固井水泥环防气窜性能要求高等技术难题。为此，通过增加窗口强度、选择稳定地层开窗等手段以确保后期开采期间分支井眼与主井眼连接处的稳定性；设计平滑的井眼轨道和提高钻井液防塌性能可保证井径规则，降低了下套管难度；采用新设计的?177.8 mm弯套管，完成了近5 000 m井深?215.9 mm分支井眼通井作业，满足了分支井眼重入和通井要求，为分支井眼套管顺利下入创造了良好的井眼条件；壁挂式悬挂器壁钩前端开口槽间隙由21.66 mm增至25.66 mm，提高了壁挂成功率；三凝水泥浆体系配合控压平衡法固井技术，保障了分支井眼溢漏同存条件下的固井质量，一界面合格率97.6%、二界面合格率100%。现场应用表明，配套技术能够满足深层高温高压含硫五级分支井钻完井作业要求，该分支井钻完井作业的成功实施可为后续五级分支井技术的推广应用提供借鉴。

Drilling and completion technology for 5-multilateral sulfur-bearing gas wells with high temperature and high pressure in Sichuan Basin

Well MX023-H1 is a 5-multilateral well in the gas reservoir in Longwangmiao formation, Sichuan Basin, and the purpose of drilling this well is to verify the adaptability of multilateral well technology in the efficient development of deep carbonate gas reservoirs. As the first level five multilateral sulfur-bearing gas well with high temperature and high pressure in China, the drilling and completion operation of the multilateral borehole is facing with many technical difficulties, such as high completion level, superabundant operation procedures, strict wellbore quality requirements, difficulty in running complex casing strings, and high-performance requirements for cementing sheath to prevent gas channeling. For this reason, in order to ensure the stability of the connection between the multilateral wellbore and the main wellbore during the later production period, the measures such as increasing the window strength and selecting stable formation windows were taken. Designing smooth borehole trajectory and improving the anti-slump performance of drilling fluid can ensure an inerratic well diameter and reduce the difficulty in running casing. By using the new designed ?177.8 mm curved casing, the drafting operation of ?215.9 mm multilateral borehole with a length of nearly 5 000 m has been completed, meeting the re-entry and drafting requirements for multilateral borehole, and creating good wellbore conditions for the smooth running of multilateral casing. The gap of the opening groove at the front end of the wall hook of the wall-mounted hanger was increased from 21.66 mm to 25.66 mm, which improves the success rate of wall-hanging. The three-set cement slurry system combined with the pressure-controlled balance cementing technology ensures the cementing quality under the condition of coexistence of overflow and leakage in the multilateral wellbore, with the qualified rate of the first interface reaching 97.6%, and the qualified rate of the second interface reaching 100%. Field application shows that the supporting technology can meet the drilling and completion requirements for the 5-multilateral sulfur-bearing deep gas wells with high temperature and high pressure, and the successful implementation of the drilling and completion operation for this multilateral well can provide reference for the subsequent popularization and application of 5-multilateral well technology.