A Method for Determining the Reasonable Bottomhole Pressure of Constant Pressure Injection in Polymer Injection Well

Abstract

The invention relates to a method for determining a reasonable bottomhole pressure of a polymer injection well under constant pressure injection, comprising the following steps: 1) collecting constant pressure injection parameters of a target polymer flooding well group, and determining the actual injection polymerization of a polymer injection well according to on-site dynamic sampling 2) Establish a three-dimensional geological model in the control area of ​​the well group to obtain the rock fluid parameters of each grid in the control area, obtain the average formation crude oil viscosity of the well group by weighting the grid area, and obtain the average formation crude oil viscosity of the well group through the statistical control area. The average thickness ratio of the high-permeability layer and the low-permeability layer is obtained; 3) Determine the reasonable injection bottom pressure multiple; 4) Perform numerical simulation calculations on the basis of the three-dimensional geological model to obtain the polymer injection well under the condition of constant-rate polymer flooding. Stable injection bottom hole pressure, and further determine a reasonable injection bottom hole pressure. The invention is easy to apply and has strong operability, and can provide effective guidance for formulating a refined control strategy of "one well and one pressure" for polymer flooding and further improving the recovery factor.

Description

technical field [0001] The invention belongs to the field of oilfield development, and in particular relates to a method for determining a reasonable well bottom pressure for constant pressure injection in a polymer injection well. Background technique [0002] With the rapid development of the economy, my country's demand for oil resources is increasing day by day. For complex reservoirs such as heavy oil reservoirs, the degree of recovery under conventional water flooding conditions is limited, and it is urgent to use new methods to enhance recovery in the late stage of oilfield development. At present, the chemical flooding EOR technology based on polymer flooding has become the basis and key to the efficient development of domestic oilfields, and plays an important role in achieving the goal of increasing reserves and production by three barrels of oil. For reservoir development, "pressure is the soul", and the increase in injection pressure is the most important dynami...

AI Technical Summary

Problems solved by technology

If the pressure setting is too high, the injection pressure of the polymer injection well will rise too fast, the injection volume will not meet the injection requirements, or even exceed the formation fracture pressure; if the pressure setting is too low, the slope of the Hall curve will not rise significantly, and it will not be possible to economically EOR

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