Study On Pressure Increasing Of High Pressure Water Filling Block In Low Permeability Reservoir

Waterflooding in low permeability reservoir is a common secondary recovery method, but the injection process is more likely to cause damage to reservoirs emerge the high water pressure. This paper targets at block D in J oilfield,to research the way of the depressurization and increasing injection, presents a main agent for forming ultra-low Interfacial tension of surfactant, supplemented with descaling scale measures systems, to decline the water injection pressure and increase injection.From the geologic factors in the district, according to qualitative analysis of reservoir rock characteristics and quantitative analysis of the core five sensitivity tests explored injection water and formation adaptability, and carried out experimental evaluation of water-blockingin using thecores, that identified sensitivity damage and water-blocking damage, the injuries of oil and water permeability damage presentsahigher level. After analysis of the adaptability of injection water quality, apart from water and hydrocarbon of harm,we find out that there is a strong trend of scaling after the water injected into the formation,, this depressurization and increasing injection measures were identified with surfactants and descaling scale inhibitor system of thought.Then according to the type and nature of different surfactant, combines oil, formation water, ground water, filters and mixsan agent that can adapt to the formation systems, the number of ultra-low Interfacial tension value could down to10-3mN/m, and experimental formation of reverse MicroEmulsion systems. Indoors water blocking disarmament experiment, antihypertensive agent core displacement test, compatibility test, evaluation considered that the preparation of antihypertensive agent, which can change fluid flow in low permeability reservoir characteristics, lower injection pressure, laboratory experimental results are obvious.To further verify the ability of depressurization and stimulation effect,we add the antihypertensive agent in oilfield water injection well to complete the field injection tests, The one-day average of tubing and casing pressures reduced0.7MPa and0.6MPa, the injection allocation rate increased14.29%, the monthly average oil pressure droped0.5MPa, and the daily injection improved1m3, finaly21wells worked well18,85.7%. D block injection pressure decreased, reaching the desired pressure-relief stimulation effect,this research ideas and the measures way on guides imilar reservoir of development has reference meaning.