ABSTRACT

The sucker rod systems and tubing strings play a crucial role in the mechanical oil recovery process; their stability and reliability are desirable factors in optimizing oil production from a well. Although durable, these metallic downhole components can experience failure during oil recovery. These failures usually stem from accumulated fatigue induced by corrosion mechanisms. The dilapidation of these costly crucial components often leads to expensive downtimes, lost production, and unnecessary maintenance costs, which can all be exacerbated by frequent failures. It is imperative to develop a mitigation strategy to extend the run life of wells and occlude premature component failures, thereby providing cost savings.

This paper presents a field-proven methodology used to extend the run life of high-failure frequency wells in Western Canada, involving the continuous application of lubricious corrosion inhibitors. The corrosion inhibitors’ Coefficient of Friction (CoF) was quantified using a Tribometer. This bifurcate study focuses on two major aspects: a root cause analysis of the high-frequency failures and the corresponding chemical mitigation strategy to address these rampant failures. The root cause analysis showed that wellbore configuration significantly affects downhole equipment failures and hints at the inimical role of friction in inducing rampant failures, prompting the need to incorporate lubricity in the chemical mitigation strategy, especially for complex directional wells. This successful approach has been implemented in over 3000 wells and has eliminated frequent component failures while extending the run-life of wells from 700-900 days to 1650 days (over an 80% increase), resulting in cost savings. This paper showcases and elucidates an economical and pragmatic chemical mitigation strategy to address frequent well failures and optimize oil production while providing operational recommendations during drilling that are key to improving a well's long-term productivity.

INTRODUCTION

The production of hydrocarbons from a reservoir involves the drilling and interaction of a well with a reservoir, which initiates the natural flow of the hydrocarbons from the virgin reservoir to the surface. However, as production continues, the reservoir pressure is depleted, which results in a reduction of the hydrocarbon production rate due to reservoir maturity. This is usually accompanied by increased water-cut levels and a corresponding decrease in gas production, which may not only reduce but completely stop the flow of fluids from a well.

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