Exploitation technique for disgorging thick oil by pouring air to assistant steam

Abstract

The present invention provides a method for production of heavy oil reservoir. It is technically characterized by that in the cyclic steam injection and steam-flooding process it utilizes air injection to raise recovery efficiency and engineering benefits. Said method includes the following steps: after the oil well is drilled, making casing sand control completion of heavy oil reservoir so as to inhibit sand inflow in after-production; constructing artificial bottom hole so as to resist high-pressure produced by injecting steam and high-pressure air; after well completion injecting hot steam (above 200 deg.C), and injecting air into same oil reservoir, reducing heavy oil viscosity, then closing well, making crude oil and oxygen gas produce oxidation reaction; after the wellhead pressure is stabilized, opening well and making production.

Description

technical field [0001] The invention relates to the exploitation of heavy oil reservoirs and the technology of improving recovery ratio. Background technique [0002] With the huge consumption of oil and gas resources, mankind will face a huge crisis of oil and gas resources in the late 21st century. In particular, China, as a big energy consumer, imports more than 100 million tons of crude oil annually. Heavy oil occupies a very important proportion in the entire oil and gas resources, and is considered to be one of the important components of future alternative energy sources. Enhanced heavy oil recovery will help maintain domestic crude oil production and ensure energy supply for domestic economic development. [0003] Heavy oil occupies a large proportion of the world's oil and gas resources. According to statistics, the reserves of heavy oil, super heavy oil and natural bitumen in the world are about 1000×10 8 t. Countries rich in heavy oil resources include Canada...

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Problems solved by technology

[0005] Polymer flooding is currently an important technology for improving medium and light oil reservoirs in my country, but the cost of exploiting heavy oil reservoirs is high, especially for viscous heavy oil, the recovery effect is not ideal

Carbon dioxide flooding can reduce the viscosity of crude oil very well, but the main problem is that the problem of gas source is difficult to solve, and the scope of application is limited

[0006] Traditional steam huff and puff and steam flooding to exploit heavy oil reservoirs mainly rely on the injection of high-temperature steam to increase the temperature of crude oil and reduce the viscosity of crude oil. The effect is better for shallow oil fields, but for deep oil reservoirs (>1000 meters), there is a large steam heat loss. Disadvantages such as low recovery rate and poor crude oil fluidity in production wells

Combustion of the oil layer is to inject air into the oil layer for high-temperature oxidation reaction to generate heat to reduce the viscosity of crude oil. The process is complicated, and it needs to be ignited underground and maintain a high gas injection rate. The underground combustion is not easy to control, and the success rate on site is not high.

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