Gas and electric heating assisted gravity oil drainage technology

Abstract

The invention belongs to a technology of well drilling, well completion and oil extraction in oil fields, which is mainly applied to exploitation of thick oil reservoirs, in particular relates to a gas and electric heating assisted gravity oil drainage technology. By adopting an upper horizontal well and a lower horizontal well or combining a straight well at the upper part and a horizontal well at the lower part, the two wells perform the double electrode action for heating oil reservoirs (mainly oil reservoirs among wells) in a distributed way on the spot, thereby avoiding the heat loss of the ground and shafts, improving the heating efficiency and obviously weakening the adverse effect of two-phase flow of oil water because of no injected water; and on the other hand, gas (N2, CO2, flue gas or natural gas and the like) is injected into the well at the upper part, wherein on the one hand, the gas is collected at the tops of the oil reservoirs to form gas caps, thereby increasing the stratum energy, keeping the stratum pressure, assisting the gravity oil drainage and simultaneously performing the action of heat insulation; and on the other hand, the injected gas can properly enlarge heat waves and volume, thereby improving the heating effect. The technology of the invention can be used as a technology of conversion and exploitation of thick oil in old areas or a technology of production and exploitation of thick oil in new areas.

Description

Technical field [0001] The invention belongs to oil field drilling, well completion and oil production technology, mainly used in the production of heavy oil reservoirs, in particular to a gas and electric heating assisted gravity oil drainage technology. Background technique [0002] Steam injection recovery technologies, such as vertical well steam huff and puff, horizontal well steam huff and puff, composite steam huff and puff, and steam-assisted gravity drainage, are currently relatively mature and effective heavy oil thermal recovery technologies. However, steam injection thermal recovery technology still has the following deficiencies: first, the heat loss on the surface and the wellbore is as high as 20% to 30%; Steam phase separation and steam overlay in the bottom and formation. With the continuous deepening of oilfield development, it is necessary to switch to the steam injection production method and adopt new technologies for heavy oil production. [0003] Ele...

AI Technical Summary

Problems solved by technology

However, steam injection thermal recovery technology still has the following deficiencies: first, the heat loss on the surface and the wellbore is as high as 20% to 30%; Vapor phase separation and steam overriding in the bottom and formation

However, due to the weak effect of gas on reducing the viscosity of crude oil, the effect of improving the fluidity of crude oil is poor, the production speed is slow, and the practical value is not obvious

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