Chemical EOR for Heavy Oil: The Canadian Experience

Abstract

Chemical EOR methods such as polymer flooding and ASP (Alkaline-Surfactant-Polymer) are generally not considered suitable for oil viscosities over one or two hundred cp (polymer) or even less (SP/ASP). However this perception is changing, in particular due to field results obtained from a number of chemical EOR pilots or full field floods implemented in Canada in higher viscosity oil in the past few years. Canada is a country well-known for its heavy oil production; recovery processes such as Cold Heavy Oil Production with Sand (CHOPS) and Steam Assisted Gravity Drainage (SAGD) have been invented there. However cold production is limited in terms of the level of recovery it can achieve and thermal techniques also have limitations in particular when reservoirs are thin. Thus Canadian companies have been pursuing chemical EOR to increase recovery in those types of reservoirs. The aim of this paper is to review some of the Canadian projects for which public information is available. Several mostly unpublished projects will be discussed in details, and conclusions will be drawn on the applicability of chemical EOR methods in heavy oil. The practical experience gained in Canada can be applied in other regions of the globe where chemical EOR has so far not been considered or has been screened out because of high viscosity.

Historical and recent observations in polymer floods: An update review

“…Sheng et al (2015) and Zhang, Y., Wei, M., Bai, B., Yang, H., & Kang, W., (2016) suggested the applicability of polymer flooding for reservoirs with crude oil viscosities up to 150 cP and 285 cP, respectively. This viscosity range clearly contradicts technical and economic feasibility of polymer floods in viscous oils and/or screening criteria proposed by Mogollón and Lokhandwala (2013), Carss (2014), Renouf (2014) and Delamaide et al (2014a). Sheng et al (2015) explained their disagreement as a lack of understanding of the mechanisms operating in heavy oil reservoirs and based on their interpretations, discussing some aspects of the Pelican Lake polymer flood documented in the literature.…”

A database and workflow integration methodology for rapid evaluation and selection of Improved Oil Recovery (IOR) technologies for heavy oil fields

“…6 [1,8,11,22,23,35,38] . The oil recovery factor has high importance toward the selection of the most suitable IOR method, because the increased revenue derived from the additional oil produced can be the decisive factor offsetting (or not) the additional (CAPEX and OPEX) investment required.…”

Polymer Flooding of Heavy Oil - From Screening to Full-Field Extension

“…With horizontal wells, five parallel wells (2 injectors and 3 producers) such as used in Pelican Lake, Mooney and Seal (Delamaide et al 2014a) are a good pattern layout. For vertical wells, regular 5-spot patterns for instance have the advantage of a confined central producer which allows to estimate recovery.…”

“…In Seal after a successful pilot (Delamaide et al 2014a) the injection has been extended to 14 wells and the live oil viscosity varies from 3,000 to 7,000 cp (Murphy Oil Company Ltd. 2014).…”

“…Successful smaller scale pilots are also ongoing or have been completed in Argentina (6 injection and 3 production wells in an oil with a live oil viscosity of 160 -300 cp, (Hryc et al 2013)), Suriname (3 injection and 9 production wells in an oil with an apparent live oil viscosity of 300 to 600 cp, (Moe Soe Let et al 2012), the North Sea (Etebar 1997) and Canada (Wassmuth et al 2009, Liu et al 2012, Delamaide et al 2014a. The data for the documented field tests are summarized in Table 1 to Table 4.…”