低渗透致密气藏压裂气井动态储量预测新方法——以苏里格气田为例

由于地质条件及工艺措施的影响,低渗透致密储层压裂气井的生产动态与常规气井有明显不同,存在不稳定渗流时间很长等问题,致使气井的单位压降采气量、井控动态储量、泄流面积随生产时间出现动态变化。因此在试采期间难以准确求得气井的井控动态储量和泄流面积,给气田开发方案的合理编制带来很大困难。为此,以苏里格气田为例,在准确把握低渗透压裂气井生产特征的基础上,结合现代气井动态分析方法,根据先期投产区块内多口典型气井的生产数据建立了井控动态储量预测图版,能够依据气井早期的生产数据有效预测井控储量、泄流面积随生产时间的动态变化规律,对气田的建产规模和井网加密方式具有指导作用,从而降低了测试成本,避免了资源浪费。

A new approach to the dynamic reserve estimation of fractured gas wells in low-permeability tight gas reservoirs:The Sulige Gas Field as a case study

Production performance of fractured gas wells in low permeability tight gas reservoirs significantly differs from that of conventional gas wells due to different geological conditions and technical measures. They are usually challenged by such problems as the time of non stabilized seepage flow being very long, leading to dynamic variations of gas production per unit pressure drop, dynamic reserves and drainage area along with a well's production time. Therefore, it is difficult to accurately calculate the dynamic reserves and drainage area during production test, challenging a gas field's development planning. Taking the Sulige Gas Field as a case study, we first analyze the production characteristics of the low permeability fractured gas wells, and then establish chart boards for the prediction of dynamic reserves by using the production data of several typical gas wells brought on stream earlier and in combination with modern analytical methods of gas well performance. These chart boards can be used to effectively predict the change of dynamic gas reserves and drainage area along with production time according to the initial production data of gas wells and to guide the optimization of construction scale and infill drilling, thus lowering test cost and avoiding waste of resources.