A method for increasing shale oil recovery and reducing fracturing fluid flowback through integrated pressure-flooding

Abstract

The invention relates to a method for increasing shale oil recovery and reducing fracturing fluid flowback through integrated pressure-driving, including: (1) preparing self-generated fracturing fluid; (2) using self-generated fracturing fluid to carry sand for fracturing construction (3) After the fracture is formed, shut down the well and soak the reservoir according to the reaction time designed according to the temperature of the target layer and the reaction rate of the gas agent, and soak the reservoir until all the authigenic fracturing fluid reacts and fully imbibes on the fracture propagation surface; (4) Open the well and flow back the remaining fracturing fluid, and start normal oil production. The self-generated fracturing fluid is prepared by adding 2.5%-77% of gas generating agent and 0.05%-0.1% of anti-scaling agent to water-based fracturing fluid. The gas generating agent is a water-soluble compound capable of reacting with water to generate gas. The antiscalant is ethylenediaminetetraacetic acid, sodium polyacrylate or maleic acid-acrylic acid copolymer. The invention improves the shale oil recovery rate while reducing the fracturing fluid flowback volume, the gas production speed is controllable, the chemical agent is fully utilized, and has broad market application prospects.

Description

technical field [0001] The invention relates to a method for improving the recovery rate of shale oil in the field of oilfield development, in particular to a method for improving the recovery rate of shale oil by integrating pressure flooding and reducing the flowback of fracturing fluid. Background technique [0002] With the continuous consumption of conventional oil and gas resources in my country, under the background of increasing the exploration of oil and gas resources, unconventional oil and gas resources have become an important supplement to conventional oil and gas. ). my country's shale oil recoverable resources ranks third in the world, at 322 × 10 8 barrels, second only to the United States and Russia. Thanks to the maturity of multi-stage fracturing technology in long horizontal wells, the United States has carried out large-scale development of shale oil resources and has thus become a net exporter of crude oil. According to the existing shale oil developm...

AI Technical Summary

Problems solved by technology

The two-fluid method involves multi-slug injection, which increases the complexity of fracturing operations, and the gas reaction will produce salts that are ineffective for enhancing oil recovery, resulting in waste of chemical agents, which has a negative impact on controlling construction costs

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