Abstract:

In order to study the development characteristics and efficient development strategy of high-pressure gas reservoirs with continuous reefs and shoals, taking the Y gas field in Amu Darya Basin which has different development characteristics from conventional gas reservoirs as an example, the main reasons for the changes in single well productivity and connectivity were thoroughly analyzed. After systematic study of water cut rules and its adverse effect on reservoir development, researchers targeted put forward a series of development strategies. After 3 years implementation, gas reservoir development has achieved remarkable results, which can offer effective references for same type gas reservoir optimization development. The results show that: Stress sensitivity in the early stage of high-pressure gas reservoir development has a great impact on the productivity of single well dominated by low-angle fractures. As the formation pressure decreases, the influence gradually weakens. However, the stress sensitivity of single well with high-angle fractures has little influence and the productivity is maintained; When the high-pressure gas field enters the middle development stage, the connectivity is partially deteriorated; The well developed fracture area distributed along the fault zone is a dominant channel for water cut, and the water-gas ratio rises sharply after producing formation water which is uncontrollable. After shutting down the whole reservoir, the water-gas ratio will rise to a higher level; Maintaining a reasonable gas production rate is particularly important for improving development effectiveness of the continuous reef-shoal high-pressure gas reservoir; Implementing“internal control and external discharge”developing strategy to maintain the balance of gas field drainage and water cut plays an important role in preventing water from further invading into gas reservoir.

Key words:

right bank of Amu Darya, reef-shoal gas reservoir, high-pressure gas reservoir, stress sensitivity, productivity change, connectivity change, edge water cut, development strategy

摘要：

为了研究连片礁滩型高压气藏开发特征以及高效开发对策，以阿姆河盆地 Ｙ气田异于常规气藏的开发特征为例，深入剖析了引起单井产能、连通性变化的主要原因，系统研究了水侵规律及对气藏开采带来的不利影响，针对性地提出了系列开发对策，经过 ３年的严格实施，气藏开发取得显著成效，可为同类型气藏优化开采提供有效的借鉴。研究结果表明，高压气藏开发早期应力敏感对以低角度缝为主的单井产能影响大，随着地层压力降低，影响逐渐减弱，而以高角度缝为主的单井应力敏感影响小，产能保持程度较好；高压气田进入开发中期，连通性存在局部变差的现象；沿断裂带分布的裂缝发育区是水侵优势通道，见水后水气比上升快，“控水”是控不住的，全气藏关井后，水气比再上台阶；保持合理采气速度开采对连片礁滩型高压气藏提高开采效果尤为重要；持续贯彻“内控外排”开发对策，保持气田排侵平衡，对防止水体进一步侵入气藏具有重要作用。