The process of extracting low gravity, heavy oil from production wells is a practice that can induce formation damage in the reservoir that can severely impact the productivity of a well. Often times, operators will attempt to stimulate production using traditional stimulation techniques which are not always effective or practical in heavy oil reservoirs. The objective of this document is to provide practical guidance for production engineers and well managers that may be unfamiliar with well stimulation in heavy oil environments.
Extensive field experience with heavy oil well remediation has provided key building blocks for maximizing production from heavy oil producers. This document details the common types of formation damage observed in cyclic steam and steamflood environments as well as in cold non-thermal wells. The methods used to identify the potential damage mechanisms rely primarily on decline curve analysis and where applicable, wet analysis in the lab. Once a proper determination has been made, a chemical treatment program to address the specific damage mechanism can then be designed.
In many cases, a lack of understanding of the damage mechanisms in play can lead to the application or mis-application of unconventional treatments that can damage a well even further. These actions could result in the premature abandonment of an oil well with recoverable and economically viable crude. With the proper knowledge and product application, production can often be restored to pre-damage producing levels, often with sizeable incremental gains.
The combined systematic approach of evaluating production profiles, produced fluids, making proper product selections, and selecting proper placement techniques provides a recipe for a greater chance of a successful chemical stimulation program and increased production.