Through analyzing the development of large ultra-deep structural gas fields in China,strategies for the efficient development of such gas fields are proposed based on their geological characteristics and production pe...Through analyzing the development of large ultra-deep structural gas fields in China,strategies for the efficient development of such gas fields are proposed based on their geological characteristics and production performance.According to matrix properties,fracture development degree and configuration between matrix and fractures,the reservoirs are classified into three types:single porosity single permeability system,dual porosity dual permeability system,and dual porosity single permeability system.These three types of gas reservoirs show remarkable differences in different scales of permeability,the ratio of dynamic reserves to volumetric reserves and water invasion risk.It is pointed out that the key factors affecting development efficiency of these gas fields are determination of production scale and rapid identification of water invasion.Figuring out the characteristics of the gas fields and working out pertinent technical policies are the keys to achieve efficient development.The specific strategies include reinforcing early production appraisal before full scale production by deploying high precision development seismic survey,deploying development appraisal wells in batches and scale production test to get a clear understanding on the structure,reservoir type,distribution pattern of gas and water,and recoverable reserves,controlling production construction pace to ensure enough evaluation time and accurate evaluation results in the early stage,in line with the development program made according to the recoverable reserves,working out proper development strategies,optimizing pattern and proration of wells based on water invasion risk and gas supply capacity of matrix,and reinforcing research and development of key technologies.展开更多
In the fractured water drive reservoirs of China, because of the complex geological conditions, almost all the active water invasions appear to be water breakthrough along fractures, especially along macrofraetures. T...In the fractured water drive reservoirs of China, because of the complex geological conditions, almost all the active water invasions appear to be water breakthrough along fractures, especially along macrofraetures. These seal the path of gas flow, thus the remaining gas in the pores mixes into water, and leads to gas-water interactive distribution in the fractured gas reservoir. These complicated fraetured systems usually generate some abnormal flowing phenomena such as the crestal well produces water while the downdip well in the same gas reservoir produces gas, or the same gas well produces water intermittently. It is very difficult to explain these phenomena using existing fracture models because of their simple handling macrofractures without considering nonlinear flowing in the macrofractures and the low permeability matrix. Therefore, a nonlinear combined-flowing multimedia simulation model was successfully developed in this paper by introducing the equations of macrofractures and considering nonlinear flow in the macrofractures and the matrix. This model was then applied to actual fractured bottom water gas fields. Sensitivity studies of gas produetion by water drainage in fractured gas reservoirs were completed and the effect of different water drainage intensity and ways on actual gas production using this model were calculated. This model has been extensively used to predict the production performance in various fractured gas fields and proven to be reliable.展开更多
文摘Through analyzing the development of large ultra-deep structural gas fields in China,strategies for the efficient development of such gas fields are proposed based on their geological characteristics and production performance.According to matrix properties,fracture development degree and configuration between matrix and fractures,the reservoirs are classified into three types:single porosity single permeability system,dual porosity dual permeability system,and dual porosity single permeability system.These three types of gas reservoirs show remarkable differences in different scales of permeability,the ratio of dynamic reserves to volumetric reserves and water invasion risk.It is pointed out that the key factors affecting development efficiency of these gas fields are determination of production scale and rapid identification of water invasion.Figuring out the characteristics of the gas fields and working out pertinent technical policies are the keys to achieve efficient development.The specific strategies include reinforcing early production appraisal before full scale production by deploying high precision development seismic survey,deploying development appraisal wells in batches and scale production test to get a clear understanding on the structure,reservoir type,distribution pattern of gas and water,and recoverable reserves,controlling production construction pace to ensure enough evaluation time and accurate evaluation results in the early stage,in line with the development program made according to the recoverable reserves,working out proper development strategies,optimizing pattern and proration of wells based on water invasion risk and gas supply capacity of matrix,and reinforcing research and development of key technologies.
基金Project supported by the Teaching and Research Award Programfor Outstanding Young Teachers for Higher Educa-tion Institutions of Ministry of Education of China and the Fund of Ph.D.Student Supervisor of Ministry of Education of China(Grant No :20040615004) .
文摘In the fractured water drive reservoirs of China, because of the complex geological conditions, almost all the active water invasions appear to be water breakthrough along fractures, especially along macrofraetures. These seal the path of gas flow, thus the remaining gas in the pores mixes into water, and leads to gas-water interactive distribution in the fractured gas reservoir. These complicated fraetured systems usually generate some abnormal flowing phenomena such as the crestal well produces water while the downdip well in the same gas reservoir produces gas, or the same gas well produces water intermittently. It is very difficult to explain these phenomena using existing fracture models because of their simple handling macrofractures without considering nonlinear flowing in the macrofractures and the low permeability matrix. Therefore, a nonlinear combined-flowing multimedia simulation model was successfully developed in this paper by introducing the equations of macrofractures and considering nonlinear flow in the macrofractures and the matrix. This model was then applied to actual fractured bottom water gas fields. Sensitivity studies of gas produetion by water drainage in fractured gas reservoirs were completed and the effect of different water drainage intensity and ways on actual gas production using this model were calculated. This model has been extensively used to predict the production performance in various fractured gas fields and proven to be reliable.
