Low Cost Production Gains from CHOPS Wells with Extremely Viscous Oils

摘要

Production of heavy oil from Alberta’s vast reserves continues to be a costly and capital intensive endeavor. To date considerable research has been focused on mining, SAGD, in-situ combustion, and vapor extraction. A new chemical dispersant technology has been introduced in the past year that reduces the apparent viscosity of the produced fluids from wells in the heavy oil fields around Lloydminster, Alberta, reducing the power required to drive the downhole progressive cavity pumps (PCPs), allowing pumping rates to increase, and increasing daily oil production by up to 300%. The primary benefit is removing the obstacle of pump speed limitation due to high oil viscosity. CHOPS production suffers from many challenges. Principally, the cold heavy oil exhibits high viscosities, in some cases in excess of 100,000 centipoises (cPs). Over the past two decades, technological advances in downhole PCPs, rod strings, well heads, and power units have improved the ability to produce heavy oils. However, when viscosities approach or exceed 100,000 cPs these advances do not overcome the excessive drag created by the heavy oils as they travel up the production tubing. The newly developed chemistry creates a dispersion of oil in water with a much reduced overall viscosity and increased mobility. The result: more oil loading into the pump, less drag along the rod string and production tubing, lower power requirements, the ability to increase the pump RPMs and, therefore, increased oil production. This technology was developed in Western Canada and has proven itself to be successful at increasing oil production, improving on-time, and reducing servicing on Canadian heavy oil wells produced by way of cold recovery methods. This technique could be utilized in other heavy oil fields throughout the world where production rates are limited by the issues created by extreme oil viscosities.