Study On Dynamic Characteristics And Steady - Product Countermeasure Of Xishan Kiln Gas Reservoir In

Cai31wellblock xishanyao formation gas reservoir is the typical fault-block gas reservoir of low porosity and permeability. The gas reservoir was put into develop from Novermber,2005,at present, on one hand, the gas reservoir’s scale of production, the production of well and the wellhead pressure is low, it is hard to product stably; on the other hand,the degree of utilization and recovery is low, there is a great potential in the whole gas reservoir. Therefore it is need to understand the development performance of reservoir deeply, research and formulate the countermeasure to keep the reservoir stable production and development. The paper use the dynamic and static gas reservoir information obtained in the course of production. Combined the research of the geological and dynamic characteristic of the gas reservoir, to establish the geological model of the reservoir, use the method of reservoir engineering and reservoir numerical simulation technology to formulate the reasonable strategies to keep the stable production of the reservoir.The following knowledges are obtained:(1)Cai31wellblock xishanyao formation gas reservoir is poor reservoir with the low porosity, low permeability and thin throat, the heterogeneity of reservoir is strong, using the volumetric method to calculate the geological reserves of gas reservoirs again and obtain the result is27.02×108m3.(2)The most decreasing type of the production is exponential decrease; the most decreasing type of wellhead pressure is harmonic decline; The wells product the water mostly, the water production, water-air ratio is small and stable. Analysis by the method of volume and visual geological reserves consider that the water is the condensate water or the intermediate water in the inner layer.(3)Use the conventional productivity analysis method (binomial expression, exponential form, one point method), simultaneous solution method, trinomial method to analysis the early gas well production capacity. The dynamic capacity optimization method is used to analyze the capacity and pressure change over time.For the Cai31wellblock and similar gas reservoir to recommend the trinomial in theinitial stage of gas reservoir, for some wells with a production history are recommended to use unsteady capacity optimization method.(4)Based on the data of production in Cai31wellblock, by the pressure drop method, the modern production decline method, production accumulation method, the improved material balance method (material balance combined with the productivity equation, unstable combined material balance method) to calculate the single well dynamic reserves again, to evaluate the applicability of various methods. Considered that the pressure drop method is decided on formation pressure, the modern production decline method of has a strong subjectivity, the production accumulation method restricted by follow phase, the improved the material balance method can overcome the above shortcomings, has an accuracy result. Calculated the dynamic reserves is8.62×108m3, the degree of use of gas reservoir is33.25%, gas reservoir recovery degree is12.77%. (5)Use the dynamic prediction method to forecast the recovery in the existing wells offline. The gas well production stable time, critical well with liquid flow rate, recoverable reserves, abandonment formation pressure etc, under different the abandoned wellhead pressure can be calculated at the same time.(6)Comprehensive utilization of geological, seismic, logging and drilling data,to build the geological model of Cai31wellblock,The grid direction is along with the main fault direction,the grid is153×75×4,the step length is40m×40m.Distribution of the residual gas was analyzd by history matching with assistance of geological model.(7)According to the characters of reservoir geology and production, put forward the corresponding stable countermeasures:①Natural stable solutions, to optimize the gas well production;②Supercharge stable plan;③Well pattern infilling using vertical well, to optimize the vertical fracture parameter and the reasonable production;④Encryption vertical Wells and horizontal wells,optimize the horizontal well parameters and reasonable production;⑤Encryption vertical wells and fracturing horizontal wells,to optimize parameters and the reasonable production of fracturing horizontal wells;⑥Make the reasonable adjustment scheme.