Evaluation Of Reservoir Damage In Daniudi Gas Field

In recent years, along with the reduction of the increased demand for natural gas and conventional natural gas resources, people pay more attention to the development of tight low permeability reservoir, which Erdos basin in low permeability tight gas reservoir exploration and development has achieved remarkable results. Daniudi gas field is located in the eastern part of the North Erdos basin, average porosity is8.69%, average permeability of0.76mD, has the characteristics of low porosity and low permeability, is a typical low permeability tight gas reservoir. In the process of developing the tight gas reservoir, the external medium into the drilling and fracturing measures such as direct contact with the reservoir, the reservoir damage the original equilibrium state, causing damage to the reservoir. In this paper, Daniudi tight gas reservoir as the research object, based on the geological characteristics of comprehensive research, based on laboratory experiment and field test, and discusses the damage. I had done some researches into the following areas.(1)referred to a large number of literatures, understanding of the current domestic and foreign methods of reservoir indoor and field evaluation(2) the collection and collation of geological and prospecting Daniudi gas field, exploration and development status; Combined with gas analysis results of reservoir clay and capillary pressure characteristics of gas reservoir potential damage were analyzed, the results show that the gas reservoir velocity sensitivity, water sensitivity, acid sensitivity and water lock Yan Min, potential harm; The indoor fluid sensitivity and stress sensitivity experiment, found in salt sensitivity and alkali sensitivity based fluid sensitive gas reservoirs, affecting velocity sensitivity, water sensitivity and acid sensitivity; stress sensitivity in the experiment of permeability hysteresis pHenomenon, should be fully recovered permeability cannot force is reduced, the evaluation results show that the stress sensitivity medium to high;(5) damage experiment indoor completion fluid and fracturing fluid, results show that the particle blocking, water sensitivity is a main factor for causing the completion fluid damage; cake and water lock is the main factors caused by fracturing fluid damage(6) test derivation of vertical zone two radial flow, finite conductivity vertical fracture interpretation model, and use this model to two, well mouth pressure recovery of well test interpretation by using SapHir software, according to the skin factor is obtained, the evaluation of reservoir damage.