Method for a priori estimation of effective radial permeability to enhance the informativity of interpretative value of distorted pressure recovery curves in horizontally completed wells

Effective radial (horizontal) permeability is a crucial characteristic of a fluid-saturated reservoir. Understanding this parameter assists in addressing various scientific and practical challenges in the oil and gas industry.

Effective radial permeability is determined through hydrodynamic studies conducted under unsteady filtration conditions. In the current state of a developing reservoir, these methods enable the estimation of this parameter while considering the geological and field contexts at the time of measurement. However, certain circumstances — such as inadequate well shut-in time, noisy bottom-hole pressure measurements, technical problems with the lift system, or deviations from operational procedures — can lead to significant distortions in recorded time-dependent reservoir responses.

This results in ambiguous interpretations and diminishes the informative value, particularly in wells with complex completion geometries. In such cases, methods for a priori assignment of initial estimates of sought parameters, including effective permeability, before processing pressure curves become valuable and necessary. One approach involves a prediction method based on statistical models that utilize indirect indicator assessments. This paper aims to describe the sequence of steps involved in implementing an algorithm to determine initial estimates of effective radial permeability. This algorithm employs both dimensional and dimensionless criteria. They are set of quantities, which reflect the combination of geometric features of the wellbore, physicogeological properties of the reservoir, the actual energy characteristics of the production object, and field data. The paper used the conclusions drawn from geophysical and hydrodynamic studies interpretations as the initial data. This work applied mathematical statistical tools to achieve the required solutions.

The proposed methodological approach is suitable for processing pressure curves that are complicated by side effects, while ensuring reliable estimates of the effective radial permeability of the reservoir. This method can be applied to any well where the necessary data for calculations is available.

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