致密气藏排水采气实践及思考

Practice and Thinking of Tight Gas Drainage Recovery

苏里格致密气藏气水关系复杂,地层水分布范围广,气井普遍产水。此类气藏特有的低渗透、低压、低丰度,导致供气能力不足,气井产气量较低且递减过快,在全生命周期内均存在严重的积液现象。为了实现致密气田持续稳产、降本增效,研发了以泡沫排水、速度管柱和柱塞气举三大主体技术为主的排水采气技术系列及关键配套工具,形成了气井全生命周期排水采气技术政策,满足气田差异化应用需求。针对特殊井况,研发水平井柱塞排水采气技术和套管柱塞排水采气技术,有效解决复杂井筒排水采气技术的应用瓶颈。形成φ50.8mm连续油管完井生产一体化技术,满足气井高效排液需求,节省生产成本。构建的智能气井管控平台,有效解放现场管理人力,实现气井智能化管理。针对现有排水采气技术难题,提出了排水采气技术攻关方向,需持续探索具有致密气特色的排水采气系列技术,不断突破致密气可采气量下限,进一步支撑气田高质量发展。

The gas-water relation is complicated in Sulige tight gas reservoirs with a wide scope of formation water distribution.The gas well in the area is usually water-bearing.The unique low permeability,low pressure,and low abundance of such gas reservoirs lead to insufficient gas supply capacity,low gas production and rapid decline in gas wells,and serious liquid accumulation in the entire life cycle.To keep production of the tight gas field stable and cost-effective,three backbone technologies–foam drainage,velocity string and plunger gas lift–were developed as the main technological series of drainage gas recovery and the key auxiliary tools.As a result,the technological policy for drainage gas recovery was formulated for the life cycle of a gas well to meet the need for differentiated applications at the gas fields.Focusing on the special well conditions,the horizontal well plunger drainage gas recovery technology and casing plunger drainage gas recovery technology were developed to effectively solve the bottlenecks for application of the complicated wellbore drainage gas recovery technology.The 50.8mm-diameter coiled tubing completion and production integration technology was developed to satisfy the demand for high-efficiency drainage of gas wells,saving the production cost.The intelligent gas-well management platform was established to liberate manpower from on-site management and bring the gas wells under intelligent management.The drainage gas recovery technology was studied in the light of the existing technological bottlenecks.It is necessary to continue the research on the characteristic technological series of tight gas drainage recovery,make continuous breakthroughs in the lower limit of recoverable tight gas volume and further promote high-quality development of gas fields.