Method and system for exploiting lamellar super-heavy oil deposit

Abstract

The invention relates to a method and a system for exploiting lamellar super-heavy oil deposit. The method comprises the following steps of: arranging a multi-bore well, a central steam injection well and a producing well in an exploitation region; closing the central steam injection well and the producing well and performing steam stimulation by using the multi-bore well until the temperature ofeach oil layer reaches the temperature corresponding to a second-order inflection point of a crude oil viscosity-temperature relation curve; opening the multi-bore well and the central steam injection well and injecting steam into the oil layers; closing the multi-bore well and the central steam injection well for soaking; and opening the producing well to perform steam driving exploitation. In the method, the multi-bore well is used for performing the steam stimulation according to the characteristics of the multi-layer super-heavy oil deposit; a plurality of branch wells are drilled in a main pitshaft by a side-tracking method and are embedded into each oil layer of the oil deposit; the whole exploitation range is heated comprehensively and three-dimensionally; steam waves and regions as big as possible are formed with the cooperation of the central steam injection well; and the mobility of the super-heavy oil and the oil-water mobility ratio are improved, and the problems that the lamellar super-heavy oil has high viscosity and is difficult to drive and the steam sweeping range is small are solved.

Description

technical field

[0001] The invention relates to a thermal recovery method and system for super-heavy oil (viscosity greater than 50000mPa.s), in particular to a production method and system for layered super-heavy oil reservoirs. Background technique

[0002] According to my country's heavy oil classification standards, crude oil with a viscosity greater than 50,000mPa.s belongs to super-heavy oil. Taking the super-heavy oil in Shuyi District of Liaohe Oilfield as an example, the viscosity of super-heavy oil ground degassed crude oil is as high as 20×10 4 At about mPa.s, the flowable temperature is about 80°C. When the oil layer temperature is lower than 80°C, the crude oil does not flow under the underlying conditions, and the oil well production drops rapidly to zero. Due to the poor fluidity of ultra-heavy oil, the investment in thermal recovery of super-heavy oil is relatively high, and the risk of exploitation is greater than that of ordinary oil reservoirs. Therefore, ...

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