Material Balance Equation In Applied Research, Water-drive Gas Reservoir

With the development of the world oil industry, the exploitation of gas reservoirs are increasing speedily. The gas reservoirs are classified as constant-volume gas reservoirs and water drive ones according to water flooding. A large proportion of developed gas field are water drive gas reservoirs so that making a deeply study of it will contribute to exploiting a gas reservoir more rationally and more efficiently. The material balance equation was the first choice means when petroleum reservoirs engineers research how to develop the water drive gas reservoirs, because it takes no account of complicated underground seepage and demands less data, the water influx is the primacy puzzle utilizing the material balance equation to study the water flooding gas reservoirs because of the incursion of water that makes the difficulties in calculating geological reserves and dynamic analysis.On the base of the studies and analyses on a great number of related references, this paper starts with the classifying of the water drive gas reservoirs and the identifying the water drive gas reservoirs in forepart. A general expression material balance equation is proposed and discussed that can apply in constant-volume reservoirs and transfiguration reservoirs through analyzing of the conventional method, on the basis of optimality principle, a novel optimization method of calculating geological reserves and water invasion rate of water drive gas reservoirs is proposed in this paper basing on the material balance equation, and the genetic algorithm is performed to obtain the results of geological reserves and water invasion rate of water drive gas reservoir directly.a new optimization model of estimating pattern recognition of water influx and calculating the aquifer size is established on basis of the material balance equation and water flooding features. A new methods presented can predict the recovery of water drive gas reservoirs according to production data. The new method is developed to overcome the limitation of long testing times required to reach stabilization in the flow test through analysing the conventional deliverability Analysis, on base of that, combining the material balance equation and reservoir production system we introduce the conception of production time, then the dynamic optimization allocation model of water drive gas well is established. The software for optimization calculation in water drive gas reservoirs by the material balance method is programmed by Visual C. Comparative analyses of the results from this and other methods indicate that the proposed method is simpler and rapider to use as well as accurate and reliable.