Success Of Water-Alternating-Steam-Process for Heavy Oil Recovery

Abstract

The recent period of depressed oil prices which reached as low as $US 5.97/bbl for heavy oil drove major reviews in heavy oil recovery economics, and led to a substantial shift in the operation of four (4) of Petrotrin's thermal projects. The shift was predicated upon key factors such as:experience derived from the North Fyzabad project, a mature steamflood which was converted to a heat scavenging project in 1996the need to assure project viability by maintaining a reasonable lifting cost.at least sustain the present level of decline rates associated with each project. In February 1999, North Palo Seco, Apex Quarry and Bennett Village, three (3) mature thermal projects at Petrotrin were placed on the water-alternating-steam-process (WASP) and another, Central Los Bajos was converted in August 1999. The four (4) projects are in close proximity each exploiting the Lower Morne L'enfer sandstone and their operating and reservoir characteristics are quite similar. In two (2) of the schemes, selected patterns were converted to WASP, the other patterns being kept on continuous steam. The criteria for pattern selection were pattern temperature, steam-oil-ratio, produced WOR, susceptibility to steam breakouts, and minimal alteration to main piping system. The paper discusses capital expenditure for the conversion which was kept to an absolute minimum, operating cost which was subsequently reduced; profitability which increased; reservoir response to water injection which resulted in an increase in oil production rate and problems associated with implementation. The paper also discusses techniques of day-to-day flood monitoring, highlights operational problems and presents future operating strategies.

Evolution of Field Rejuvenation

“…The integration of these maps led to the identification of various types of opportunities. They include exploration type (2), infill drilling (5), step out (8), targeted infill (10), truncation play (6), updip attic (6), and underperforming pay (6). These forty-three opportunities represent an increase in the reserve base of 2.8 MMBO and can boost production 3.5 fold one year after implementation (Fig.…”

An investigation on economy and CO2 emission of water alternating steam process (WASP) using response surface correlation

“…They claimed that WASP eliminated early steam breakthrough and channeling problems, reduced fuel consumption for steam generation and improved incremental oil sale (Hong and Stevens 1990). A successful WASP has also been reported in some other fields such as North Palo Seco, Apex Quarry, Central Las Bajo, and Bennett Village (Ramlal and Singh 2001).…”

Técnicas para el mejoramiento de la inyección continua de vapor

“…La uniformidad de este frente, también conocido como conformance, es afectada por la variación espacial de la permeabilidad en el yacimiento, resultando en una pobre eficiencia de barrido vertical debido a que el vapor inyectado circula más rápido en zonas de alta permeabilidad. Por su parte, el efecto de override ocasiona la ruptura prematura del vapor en los pozos productores, acelerando el incremento de la relación vapor/aceite (Ramlal, 2000). Estos problemas pueden ser tratados con la aplicación de solventes, geles, espumas o la inyección alternada de agua caliente, los cuales han demostrado promover el mejoramiento del barrido del vapor y controlar de la movilidad de los fluidos en yacimientos calentados de esta manera obteniéndose una producción de aceite incremental o acelerada y la reducción de costos operativos asociados a la producción de aceite.…”