The Sensitivity Evaluation Of Dense Oil And Gas Reservoirs Of Jilin

The well block core of Yitong, Wangfu, Dehui and Rang-Well belong to ultra-low permeability core, which the well block core of Wangfu, Dehui and Rang-Well are classified in Nada Xi level of core permeability. Oil and gas reservoirs are the key research blocks, where rock almost don’t have flowing capacity. According to the reservoir characteristics of oil-field and fracturing case, The Jilin Oil-field production areas (Yitong, Wangfu, Dehui, Rang-Well block) of ultra-low permeability cores were made joint, which mesh seam types simulate natural fractures and single-slit type simulate artificial fracture. After making joint, the permeability of core focus on 50-100×10-3μm2, the flow capacity of core also increased. Study on clay minerals and whole-rock mineral analysis of reservoir core of four blocks, and predict the sensitivity of each reservoir block what based on lithology theoretical studies. With details as follows:the whole rock mineral content of Rang-Well Quan-four block serve as 45.8% quartz,8.4% feldspar,25.1% plagioclase,5.3% calcite, and clay mineral content of 15.4% which illite accounts the absolute amount of clay minerals for about 3.39%, illite/smectite at around 2.77%,0% kaolinite, chlorite at about 9.24% ,0% montmorillonite; The whole rock mineral test results of Yitong double-tow horizons of Jilin Oil-field:91.7% quartz, clay mineral content of 8.3% which illite accounted for about 3.57% in the absolute amount of clay minerals, illite/smectite at about 4.48%,0% kaolinite, chlorite at about 0.25%,0% montmorillonite; The whole rock mineral content of Dehui block serve as 52.1% quartz,4.3% feldspar,27.6% plagioclase,3.2% calcite, and clay mineral content of 12.8% which illite accounts the absolute amount of clay minerals for about 3.58%, illite/smectite at around 4.48%,0% kaolinite, chlorite at about 4.74%,0% montmorillonite; The whole rock mineral content of Wangfu block serve as 38.3% quartz,20.3% plagioclase,21.4% calcite,2.4% anhydrite and clay mineral content of 17.6% which illite accounts the absolute amount of clay minerals for about 5.28%, Iraq/fudge layer at about 9.15%,0% kaolinite, chlorite at about 3.17%, 0% montmorillonite; By indoor evaluation experiments of reservoir sensitivity analysis, Evaluate velocity sensitivity, salt sensitivity, water sensitivity, acid sensitivity, alkali sensitivity, pressure sensitive and temperature sensitive of each block formation. Rang-Well block, oil-field is a strong velocity-sensitivity, medium weak water-sensitive, medium strang acid-sensitive, weak alkali-sensitive, strong pessure-sensitive, strang temperature-sensitive oil reservoir. Yitong block, gas and oil layer is a medium strong velocity-sensitivity, medium strang water-sensitive, weak acid-sensitive, weak alkali-sensitive, strong pessure-sensitive, medium strang temperature-sensitive gas and oil reservoir. Dehui block, gas layer is a strong velocity-sensitivity, strang water-sensitive, medium weak acid-sensitive, weak alkali-sensitive, strong pessure-sensitive, strang temperature-sensitive gas reservoir. Wangfu block, gas layer is a strong velocity-sensitivity, strang water-sensitive, weak acid-sensitive, strang alkali-sensitive, strong pessure-sensitive, strang temperature-sensitive gasl reservoir. Through research on the mechanism of injury was a variety of working fluid apply in the construction process of Jilin oil-field block, We can see that not only the external fluid itself influence the structure formation of porosity and permeability but also due to external causes of the porosity and permeability structure change, in essence, the formation will have a sensitive injury, and ultimately will result in reduced oil permeability, clogged pores, thereby affecting the oil and gas production and damaging reservoir. But through a combination of oil formation evaluation results and related geological characteristics of the sensitivity of reservoir, basis to understand the reservoir characteristics and potential harm caused by the external working fluid, targeted research on the four protected working fluid which adapt Jilin Oil-field (killing fluid, perforating fluid, flushing liquid, water lock agent), you will find that the protection type fluids make the recovery rate value after damage reservoir greater than 95%, has a good role in protecting the reservoir, can effectively improve oil and gas development. According to laboratory experiment combined analysis study construction site found that, in the construction process, the targeted use of the working fluid system combined with the sensitivity of evaluation results for the construction, can achieve the effect of a higher level of protection of the reservoir.