Capacity Analysis And Development Effect Evaluation Of The Gas Injection Condensate Gas Reservoir In The Tooth

Yaha condensate gas reservoir belongs to the high condensate oil condensate gas reservoir. The reserves is very large and the differential pressure between strata pressure and dew-point pressure, It is very difficult to develop. Since the operation,it was tapped by the way of injecting dry gas, which results in pressure declining slowly and the production keeping highly, be sure the production of condensate as much as possible. Therefore, in view of above issues, in order to meet the requirements of stable production time, it is particularly important to research on deliverability evaluation method and reasonable production techniques for Yaha condensate gas reservoir.Based on the literature research home and aboard, this paper synthetically used the theories and methods of many disciplines such as seepage mechanics, gas reservoir engineering, well test analysis, optimization algorithm and so on. Combined with the geologic and exploitation features of Yaha condensate gas reservoir, this paper studied the following several subjects and got the corresponding research results:(1) The structure characteristics, sedimentary characteristics, reservoir properties and fluid characteristics of Yaha condensate gas reservoir are analyzed and summarized. The production decline law, law of the pressure drop and water production characteristics of gas reservoir and single well are studied.(2) Researching the calculation method of conventional critical parameters for gas reservoir and combining with the characteristics of fluid phase in the condensate gas reservoir, to establish the calculation method of the pseudo critical parameters for condensate gas reservoir. On the basis of this, the calculation method of deviation factor is selected for the analysis of the gas reservoir.(3) The conventional deliverability evaluation method is analyzed, combining with Well test data processing method, to carried out the productivity evaluation of the condensate gas reservoir stability by stability test data. The applicability of this method is studied. Because of the Yaha condensate gas reservoir has poor serious condensate phenomenon. The Free flow rate and the actual production error is very large, so the applicability of the conventional deliverability evaluation method in Yaha condensate gas reservoir is poor.(4) Based on the percolation characteristics of condensate gas reservoir, the productivity equation considering the oil and gas quasi steady state is derived, the history matching objective functions of production and bottom hole flowing pressure are established by use of production data. Using this method to calculate and evaluate the productivity of gas well, and the production distribution effect is good, and the result shows that the method is reliable.(5) In the light of Yaha condensate gas reservoir productivity test curve has a negative slope, the deliverability equation of condensate retrograde condensate skin factor is derived. Combined binomial productivity equation with skin factor, to corrected the test production and solve the capacity curve slope is negative, obtaining the correct gas well productivity.(6) Yaha condensate gas reservoir tappes by the way of injecting dry gas, which use the principle of superposition of pressure drop in seepage mechanics. Each source or sink in the space of a point of pressure can be added linearly and the actual pressure point will be affected by the interaction of several wells, so the Pressure drop superposition productivity evaluation method considering is given out. Using this method to calculate and evaluate the productivity of gas well, and the production distribution effect is good, and the result shows that the method is reliable.(7) Considering the condensate gas reservoir for the development characteristics of injecting dry gas.Selecting the capacity?reserves producing situation the degree of formation pressure maintenance?the changing law of formation water and the sweep efficiency, and so on, for the study. Analysis the relationship between the above indexes and develop concepts. Reference the develop concepts prediction index and the exchange with the field staff, the development effect is good.