Study On The Effect Of Long - Term Water Filling On Reservoir Physical Properties And Development Effect

At present, many old oil fields have high water cut, due to the long term water flooding, the micro pore structure of reservoir has undergone great changes, its heterogeneity is more severe than the early stage of development, mining more difficult. Water flooding is a widely used method in oil field. At present, water flooding method for oil field account for a large proportion on the world. In the water flooding process, the water flooding not only drive for oil and gas in reservoir, but also to the reservoir properties and reservoir pore structure have a great impact. So the microscopic characteristics of the reservoir has changed more than before the development. Study before and after the reservoir variation of microscopic characteristics at long-term water flooding, it plays an important role to guide the field program adjustments, enhanced oil recovery and improve the ultimate recovery.High water cut oil field logging core data and oil field dynamic data show that, because the long-term water flooding to the reservoir, the reservoir macro structure, micro structure and the heterogeneity compare with the early development which have occurred significant changes. particularly the main flow parameters (porosity, permeability, relative permeability, capillary pressure, oil viscosity, rock matrix, pore network etc.) had great changes. These parameters had a tremendous impact on the distribution of residual oil.Study the microscopic characteristics of variation of the reservoir, in different regions, different fluid properties, the different lithology, at the different displacement speed, The parameters of reservoir have the different changes. Analyze the specific reservoir properties in different parts, it is important to guide the continued efficient development of oil fields.This article does mainly work, which sum up the major in the following areas:(1) At the different displacement speeds, injecting water or white oil displace to the core at long-term, analyzing the core porosity and permeability variation. Water flooding have impact on relative permeability and rock wettability of the reservoir. And measure the quality of the core changes before and after displacement.(2) According to the core permeability decreased, establish the microscopic parameters of the dynamic evolution of the reservoir model;(3) Analyze the high porosity and permeability characteristics of the reservoir which possibly occurred sensitivity:rate sensitivity, water sensitivity, stress sensitivity. To identify that, the reservoir have speed sensitivity, water-sensitive and the degree of sensitivity, when it in contact with the outside fluid. Through systematic reviews, comprehensively study, proposes drilling, completion, stimulation design proposals.(4) Study the reservoir parameter changes which have an effect on development, mainly from the vertical, the plane heterogeneity, reservoir pore structure and the layer of micro-dissection and other factors.