Predication method for spray-stopping stratum pressure of oil well

Abstract

The invention relates to a predication method for spray-stopping stratum pressure of an oil well. The method is characterized by including the following contents: 1) establishing a typical flow oil well production system node analysis model; 2) calculating oil and water two-phase relative permeability Krw, Kro and a zero dimension fluid collection index JDL, and obtaining an oil and water two-phase relative permeability curve and a zero dimension fluid collection index curve; 3) on the basis of a fluid collection index PI0 when a water content of an oil well is 0 and the zero dimension fluid collection index curve, calculating different water contents of nodes in the well and inflow curves in different stratum pressure conditions; 4) on the basis of the minimal output pressure PDSCmin needed by crude oil in the mouth of the well, calculating outflow curves of the nodes in the well in different water content conditions; and 5) on the basis of the inflow curves and the outflow curves of the nodes in the well, determining a critical spray-stopping state of the oil well, and calculating the critical spray-stopping stratum pressure Pc of the oil well.

Description

technical field [0001] The invention relates to a method for predicting formation pressure of an oil well without blowout, and relates to the technical field of oil field development. Background technique [0002] The prediction of the formation pressure of the oil well without blowout is an important factor for determining the production capacity construction scale of the oilfield and changing the lifting mode of the oil well on a large scale. Therefore, it is of great significance for the accurate prediction of the formation pressure of the oil well without blowout. [0003] At present, in the prior art, some experts and scholars have used methods such as mathematical statistics and node analysis to predict oil well blowout stop pressure. Among them, the physical meaning of the mathematical statistical method is not clear, and is limited by the statistical sample points, so the scope of application is limited. In addition, when using the nodal analysis method to predict f...

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Problems solved by technology

Among them, the physical meaning of the mathematical statistical method is not clear, and limited by the statistical sample points, the scope of application is limited

In addition, in the process of predicting the formation pressure without injection using the nodal analysis method, only the difference of the outflow curve under different water cut conditions is considered, and the influence of the water cut on the fluid production index and inflow curve of the oil well is not considered, so the prediction accuracy is not high

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