法国拉克、麦隆气田对安岳气田龙王庙组气藏开发的启示

四川盆地安岳气田磨溪区块下寒武统龙王庙组气藏是我国近年发现的一个特大型整装复杂碳酸盐岩气藏,该气藏具有储层孔隙度低、裂缝孔洞发育、气水关系复杂、中含硫化氢、气井单井产量高和储量规模大等特点,国内尚无类似气藏开发先例可资借鉴。为此,基于CC和IHS数据库,通过多指标的对比分析,筛选出法国的拉克和麦隆两个相似气田并进行了开发规律剖析,同时结合大量相关数据统计分析,形成了该类气藏在战略定位、前期评价、开发技术政策制定、动态分析和风险管理策略方面的6点经验启示:①大型主力气藏保护性开发,适当降低采气速度可以确保长期安全稳定生产;②试采周期越长,对气藏特征的认识越清楚,可为高效开发打下坚实的基础;③多种方法量化描述裂缝,综合评价裂缝对气田开发的影响;④依据气藏特点,确定合理的单井配产;⑤生产井集中部署在构造高部位,射孔层位尽量远离气水界面,部署观察井监测水体动态;⑥高度重视储量风险评估,采取滚动勘探开发和弹性指标策略降低开发风险。上述经验启示对于龙王庙组及类似气藏的高效开发具有指导作用。

Enlightenments of Lacq and Meillon gas fields in France to the development of Longwangmiao Fm gas reservoirs in the Anyue Gas Field,Sichuan Basin

The gas reservoir of Lower Cambrian Longwangmiao Fm in Moxi Block of the Anyue Gas Field, Sichuan Basin, is a supergiant mono-block complex carbonate gas reservoir which was discovered in China in recent years. It is characterized by low porosity, well-developed fractures and vugs, complex gas–water relationship, medium H2S content, high single-well deliverability and abundant reserves. So far, no similar gas reservoir has been developed in China for the reference. In this paper, two similar gas fields (i.e., Lacq and Meillon) in France were selected after multi-index comparative analysis was performed on C&C and IHS databases. The development laws of Lacq and Meillon gas fields were analyzed. Based on statistical analysis of abundant data, six enlightenments were concluded in terms of strategic orientation, preceding assessment, technical strategy formulation, dynamic analysis and risk management. First, carry out protective development on principal gas reservoirs by reducing the gas production rate to ensure its long-term stable exploitation. Second, extend production testing period to understand the characteristics of gas reservoirs more clearly and provide a solid foundation for high-efficiency development. Third, characterize quantitatively the fractures by multiple methods and evaluate comprehensively the effect of fractures on gas field development. Fourth, determine reasonably the well proration according to the gas reservoir characteristics. Fifth, concentrate producing wells at structural highs, lay perforation intervals away from the gas–water contact as far as possible and deploy observation wells to monitor water behavior. And sixth, focus on reserve risk assessment and adopt progressive exploration & development and elastic index strategies to reduce development risks. These enlightenments provide a guidance for the high-efficiency development of Longwangmiao Fm and similar gas reservoirs.