A method of fracturing and flooding to improve the recovery economic efficiency of thin poor reservoirs in old oilfields

Abstract

A fracturing flooding method for improving the recovery economic efficiency of thin and poor reservoirs in old oilfields. According to the method of the present invention, on the basis of reservoir evaluation and remaining oil description, the fracturing measures and technological schemes are designed in a targeted manner, and finely controlled fracturing technology is adopted to inject high-intensity fracturing and oil-displacing agents into the formation in a short period of time. The fracturing oil-displacing agent with good fracturing performance and flooding effect can infiltrate into the formation at the same time as the cracks are formed in the formation, which not only increases the energy of the formation, but also efficiently washes away the remaining oil in the formation, thereby greatly improving the oil loss of the thin and poor oil layer. recovery factor. The method of the present invention combines reservoir transformation, energy supplement and chemical flooding into one, can realize comprehensively enhanced recovery, rationally optimize the construction parameters in fracturing and the performance of fracturing oil displacement agent, and form "fracturing-injection" ‑Flooding and washing” integrated new enhanced oil recovery technology realizes the organic combination of reservoir stimulation technology and reservoir development integration, and improves the economic efficiency of the recovery of thin and poor reservoirs in old oilfields.

Description

technical field [0001] The invention relates to a fracturing oil displacement method for improving the recovery rate of thin and poor reservoirs in old oilfields, in particular to a comprehensive method for improving oil recovery in combination with reservoir reconstruction, energy supplementation and chemical flooding, which belongs to the development of oil and gas fields technology field. Background technique [0002] At present, most of my country's oil production comes from old oil fields. The remaining reserves of old oil fields are quite considerable, and there is huge room for tapping the remaining oil. In the foreseeable future, old oil fields will still be the main force of oil supply. The economical and effective development of mature oilfields that have entered the stage of high recovery and high water cut will become a major challenge for the Chinese petroleum industry. Therefore, continuous exploration of new technologies to improve the recovery of mature oilfi...

AI Technical Summary

Problems solved by technology

The industrial development of thin and poor reservoirs has been explored for many years. Under the current development conditions, the overall production status of thin and poor reservoirs still needs to be improved. A considerable part of thin and poor reservoirs is difficult to effectively develop through traditional secondary oil recovery and tertiary oil recovery technologies.

[0003] Under the action of binary and ternary compound chemical agents in long-term water flooding development, adjusted injection water flushing and chemical flooding enhanced oil recovery technology, the physical property conditions, fluid properties and remaining oil distribution of thin and poor reservoirs in old oilfields have been compared with conventional ones. Reservoirs vary greatly, and the application of EOR technology that has achieved good results in conventional oil reservoirs is limited, and the expected EOR effect cannot be achieved

Reservoir stimulation technologies such as conventional acidizing and fracturing are difficult to implement, the cost of measures is high, and the range of enhanced recovery is limited; the control range of conventional fracturing fractures is limited, and it is difficult to establish an effective displacement relationship between injection and production; It is difficult to control the loss of control, and the fracturing fluid will block or damage the formation, which will affect the effect of the measures; the thin reservoir has strong heterogeneity, large difference in physical properties, high clay content, and the conventional energy supplement method cannot be effective; the microscopic characteristics of the thin reservoir are complex , the radius of the pore throat is small, and it is difficult to develop a suitable high-efficiency flooding agent, and the conventional chemical flooding effect is limited

[0004] In summary, a single conventional enhanced oil recovery technology or a simple combination of several technologies cannot solve the problem of thin and poor reservoirs in old oilfields

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