Compound huff-puff oil recovery method by using steam and oil-soluble viscosity reducer

Abstract

The invention provides a compound huff-puff oil recovery method by using steam and an oil-soluble viscosity reducer. The method comprises the following steps: a. embedding of a steam injection pipe column: the structure of the pipe column is a uniform steam distribution pipe column which is sequentially provided with a uniform steam distribution valve and a compensator from the bottom to top, an injection and recovery integrated pump is connected with the upper part of the pipe column, an oil pipe is arranged on the pump, and a sub-critical steam injection well mouth is adopted; b. injection of the viscosity reducer: firstly the oil pipe is filled with the oil soluble viscosity reducer, then a casing valve is closed, and the oil soluble viscosity reducer is continuously injected into a well bore; c. steam injection: the steam is annularly injected via an oil jacket; d. well soaking: the well remains soaking for 2-7 days after the steam is completely injected; e. open flow: when the pressure of the well mouth drops to 0.5MPa / day, open flow is controlled by an oil nozzle; and f. pumping startup: in the case of open flow up to the liquid quantity of 3t / d, the injection and recovery integrated pipe column is adopted for starting pumping.

Description

Technical field: [0001] The invention relates to the technical field of oil recovery in oilfields, in particular to a combination of steam and oil-soluble viscosity reducer for shallow ultra-heavy oil reservoir exploitation, medium-depth ultra-heavy oil reservoir exploitation and shallow extra-heavy oil reservoir exploitation Huff and puff oil recovery method. Background technique: [0002] For shallow ultra-heavy oil reservoirs, in addition to reducing the viscosity of crude oil and increasing the fluidity of heavy oil, since the oil layer is buried shallowly, the formation pressure is low, and the driving force for crude oil to flow in the oil layer is small, it is also necessary to supplement formation energy. To achieve economical and effective development. At the same time, during the steam injection process of shallow ultra-heavy oil reservoirs, there are still high steam injection pressures, which are easy to fracture the formation. After the formation is fractured, ...

AI Technical Summary

Problems solved by technology

Although these technologies can achieve certain effects, the above-mentioned technologies can only meet one of the requirements for the development of shallow super-heavy oil reservoirs, and cannot solve the production problems of shallow super-heavy oil reservoirs well and comprehensively. Therefore, there is still a need in this field for a new type of shallow ultra-heavy oil reservoir recovery technology, which can simultaneously reduce the viscosity of crude oil, replenish formation energy, reduce steam injection pressure, prevent steam overburden, and increase the drainage area.

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