A Simulation Study of a Cyclic Steam Stimulation Pilot in a Deep Carbonate Heavy Oil Reservoir in Oudeh Field, Syria

Abstract

The Oudeh Shiranish reservoir in Syria contains 5.1 billion bbls of 12-16 °API crude oil. However primary recovery factor is estimated to be only 5 to 7% of the original oil in place. To increase oil recovery, waterflood, VAPEX, microbial treatment and cyclic steam stimulation (CSS) were examined. Eventually, CSS was selected for a pilot test despite the depth of the reservoir, approximately 1600 meters, was deeper than most successful CSS projects in the world. The CSS pilot was implemented in September 2006 and suspended in November 2009. The project expanded from 2 to 24 wells. Low steam quality at the bottom of the well proved to be the most prominent challenge due to a combination of heat loss in the wellbore and relatively low steam injectivity. Only hot water reached the bottomhole when steam was injected through casing. Injection into tubing improved steam quality. Vacuum insulated tubing (VIT) produced the best, increasing steam quality to between 20 and 40% at a wellhead steam quality of 80% and an injection rate of 200 m3 CWE/day. The high pressure required to inject into the Shiranish reservoir at close to or higher than initial reservoir pressure conditions means that the latent heat of vaporization is low, compared to the typical CSS injection pressure, resulting in a less effective heating process. In the study, a new thermal simulation model was developed to examine history-matching parameters, match the well and pad performances and optimize operations if the pilot were to be continued. Excellent history matches were achieved. Forecast indicated that Shiranish CSS performance was positive and could increase oil recovery by up to 100% over cold production.

Bitumen Recovery by the SOS-FR (Steam-Over-Solvent Injection in Fractured Reservoirs) Method: An Experimental Study on Grosmont Carbonates

“…The limited number of field pilots include the Lacq Superior field in France Ferrier 1982 andSahuquet et al 1990), the Ikiztepe field in Turkey (Nakamura et al 1995), the Yates field in the USA (Snell and Close 1999), the Bati Raman field in Turkey (Babadagli et al 2008), the Wafra field in the Partitioned Zone between Saudi Arabia and Kuwait (Brown et al 2011), the Oudeh field in Syria (Li et al 2010), and the Qarn Alam field in Oman.…”

A review of development methods and EOR technologies for carbonate reservoirs

“…At the same time, the heterogeneity of carbonate reservoirs further intensifies the crossflow degree of injected steam, so there are few steam injection methods applied to carbonate reservoirs. Limited field applications include Lacq Superior in France, Ikiztepe in Turkey, Yates in the USA, Bati Raman in Turkey, Wafra in Saudi Arabia and Kuwait, Oudeh in Syria and Qarn Alam in Oman (Sahuquet et al 1990;Nakamura et al 1995;Snell and Close 1999;Babadagli et al 2008;Brown et al 2011;Li et al 2010;Smith and Parakh 2016).…”

Impact of Reservoir Heterogeneity on Steam Assisted Gravity Drainage in Heavy Oil Fractured Reservoirs

“…CSS pilot was applied in the Oudeh Shiranish deep carbonate field in Syria and was suspended later. After successful history matching of past pilot, numerical study by Li et al (2010) showed that this process can increase oil recovery by 100% more than cold production. Yuan et al (2010) created a 3D model for the Buffalo Creek Pilot Phase II of Grosmont Carbonate heterogeneous fractured reservoir and history matched the CSS pilot successfully.…”