Research On Development Adjustment Plan For531Wellblock T2_k2Low Permeability Reservoir

With great development potential, low permeability reservoirs have increased ingrowing proportion in China’s annual newly added proven oil reserves. Taking the531wellblock T2k2reservoir as an example, this paper intensively studied thecharacteristics and potentials of low permeability reservoirs.With the study area’s drilling, geological, geophysical, logging interpretation anddynamic data, the paper, basing on the further geology recognition and thecombination of dynamic and static method, obtained the low permeability reservoirs’potential distribution in this region by expoliting the evidence of subarea, thecharacteristics and influence factors of their development and usage. Selecting theexperimental zone for the numerical simulation prediction and adjustmentcountermeasures research, the paper aimed to work out the reasonable developmentadjustment schemes and achieve stable reservoir production by applying suchschemes to the favorable area. In this paper,the achieved accomplishments and thefuther understandings are as followed:1. The overall characteristics of low permeability reservoirs are the poorreservoir property, serious heterogeneity, high shale content, small pore throat radius,little reservoir elastic energy; Natural capacity, fluid flow degree, water floodingcontrol level and production ability are low, and the water flooding occurs slowly etc.Since the reservoir fluid seepage is not corresponded with the darcy’s law, and thelower rate of the reservoir permeability is, the higher the start-up pressure gradient, itis needed to overcome the start-up pressuret.2. Analysts believe that there exists some problems such as difficult to waterflooding，injection-production pattern has imperfections, fluid flow degree level is low,interlayer interferene serious,producing degree level is low etc. Aiming at theseproblems, the existing well pattern, development formation and injection-productionstructure need to be further adjusted and optimized,select the reasonable developmentways.3. With the methods of reservoir engineering and numerical simulation, studies on the remaining oil distribution of the reservoir, suggest that the plane remaining oilmainly stores in the central of study area and northwest region near fault;Longitudinal contradictions the differences of recovery percent between profile usingis big, but the main production layer (S52-1、S32-2layer), also being the main layer ofemaining oil distribution,4. The factors influencing on the remaining oil distribution of low permeabilityreservoir are as followed: threshold pressure gradient of low permeabilityreservoir,the plane and vertical heterogeneity of the reservoir, the fracture propertiesand occurrence characteristics of the reservoir, the pore structure types of the reservoir,injection-production well pattern well spacing and the corresponding relationshipsbetween perforation layers.5. Combined with existing research results, according to the characteristics,development status and potential distribution of low permeability reservoirs, weshould work out the reasonable development schemes such as the well spacing density,interval of well, the degree of pressure maintain,injection-production ratio,oil-waterwell quantity ratio, oil recovery rate etc,improve the development effect as well.