Experimental Study on Factors Influencing Recovery Degree of Tight Oil Reservoirs by Water Injection and Stimulation
In order to explore the factors affecting the improvement of oil recovery by water injection stimulation in tight oil reservoirs,a long rock ventricular stimulation experiment was conducted on the Chang 8 tight oil reservoir in the Ordos Basin.The factors affecting the recovery degree of the Chang 8 tight oil reservoir were studied,including permeability,lock-in time,injection water volume,injection rate,and stimulation cycle.The experimental results showed that,for tight oil reservoirs with Chang 8,matrix permeability affected the effectiveness of water injection and stimulation,the higher the permeability,the higher the degree of water injection and stimulation recovery;The fluid exchange efficiency between crude oil and matrix was affected by the oil soak time,the longer the soak time,the more sufficient the fluid exchange,and the higher the final recovery degree,however,there was a critical value for the soak time;The water injection volume and water injection rate were effective supplements to the formation energy,which affected the final recovery degree of stimulation,the lower the water injection rate,the easier it was to exert the capillary force's suction effect,and the better the throughput effect,there was a critical value for the water injection volume,which could easily form a dominant channel and affect the recovery effect after exceeding the critical value.This research achievement provides some reference for the efficient energy supplementation development of tight oil.
Ordos BasinTight oil reservoirsWater injection and stimulationLong core displacement
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