Microscopic Occurrence and Production Characteristics of Formation Water in Shaximiao Formation Tight Sandstone Gas Reservoir in Zhongjiang Gas Field
The study of the microscopic distribution of formation water can provide reference and basis for the optimization of favorable zone selection and gas well production system.Using thin section,scanning electron microscope,mercury injection,nuclear magnetic resonance,two-phase flow experiment,logging,and production dynamic data,the study of the pore structure,reservoir water distribution state,and production characteristics of the tight sandstone gas reservoir in the Shaximiao Formation of Zhongjiang Gas Field was conducted.The results show that the average median pore throat radius of Class Ⅰ,Ⅱ,and Ⅲ reservoirs in the Shaximiao Formation of Zhongjiang is 0.30,0.16 and 0.04 μm,respectively.Formation water exists in the form of free water,capillary water,and thin film water in the reservoir.Thin film water is widely distributed,capillary water mainly exists in the throats with a radius less than 0.100 μm,and free water can be seen in reservoir with poor matching relationship between fault and sand body and low structural position.The main source of water production in gas wells is condensate water,capillary water,and thin film water,with the overall characteristics of low water production,low mineralization,low water-gas ratio,and an increase in the latter.The evaluation and development of high water-saturated areas should primarily target Ⅰ and Ⅱ reservoirs,and production pressure differentials should be appropriately controlled during production of water-gas wells.
Zhongjiang Gas FieldShaximiao Formationtight sandstonemicroscopic occurrence of formation waterwater production characteristics
万方数据
维普
