A method to determine whether to carry out nitrogen-assisted viscosity reduction and construction radius

Abstract

The invention provides a method for determining whether to carry out nitrogen-assisted viscosity reduction and a construction radius. The method comprises the following steps: firstly determining that an oil well needs to be constructed and has a construction value, and acquiring relevant construction parameters; and analyzing and calculating flow resistance caused by a starting pressure gradient of a heavy oil reservoir and a displacement pressure established according to the pressure drop of the production of the oil reservoir, calculating (the value that the replacement pressure subtracts the flow resistance is less than 0) to determine a non-movable oil range of the oil reservoir under the current production conditions of the oil well, solving the furthest effective construction radius of a viscosity reducer, and judging whether a nitrogen-assisted viscosity reduction technique is required and the effective injection radius is equal to the furthest construction radius of the viscosity reducer by virtue of the injection gradient analysis of indoor viscosity reducer. According to the method, the condition that whether the nitrogen-assisted viscosity reducer is required for construction in situ is determined, and the furthest construction radius is determined, so that construction risks are reduced, and certain guidance can be provided for viscosity reduction construction measures.

Description

technical field [0001] The invention relates to the technical field of petroleum engineering, in particular to a method for determining whether to carry out nitrogen-assisted viscosity reduction and the construction radius. Background technique [0002] The development of chemical viscosity reduction in heavy oil cold recovery is a technology developed at home and abroad in recent years. Improve the mobility of crude oil to achieve the purpose of reducing viscosity and drag. This process is simple in construction and convenient in production management, and has gradually become an important technology for improving the recovery effect of heavy oil and super heavy oil. [0003] Nitrogen-assisted viscosity reduction, as a supporting technology for chemical viscosity reduction, has been applied in some reservoirs. Its main functions include: ① After nitrogen is injected into the formation, it increases the formation pressure near the wellbore, prolongs the stimulation period,...

AI Technical Summary

Problems solved by technology

However, as to whether to use nitrogen-assisted viscosity-reducing construction technology, experience judgments are mostly used in mines, and the determination of injection volume is basically based on laboratory experimental research for specific reservoirs. This process is time-consuming and laborious, and delays construction timing; or adopt Empirical design, which easily brings risks to construction

There is currently a lack of a method to determine whether to use nitrogen-assisted viscosity reduction technology and determine its effective construction radius, which can reduce construction risks and quickly make construction judgments

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