Surveillance And Performance Of An Existing Polymer Flood: A Case History Of West Yellow Creek
Authors: Gordon Simone P. , Owen Olivia K. 
Published: December 2007

Model studies and field tests predict that two million barrels (3 × 10(5) m3) of additional oil will be recovered by polymer flooding the Eutaw interval of the West Yellow Creek Field. Analysis of polymer-induced response in a nearby field with similar characteristics plus extensive reservoir simulation of both waterflood and polymer flood operations in the Eutaw interval polymer flood operations in the Eutaw interval were important elements in the economic analysis of this project. As a result of these studies, a polymer flood project was approved by the working polymer flood project was approved by the working interest owners, ana injection was initiated in September 1976. This paper addresses the operational considerations and the surveillance techniques that have been developed over the last three years for West Yellow Creek. Operational procedures associated with the shipping, mixing and flow control of the polymer are discussed along with the multi-faceted surveillance program that includes polymer quality monitoring, tracer surveys, fall-off tests, computer tracking, and production review. production review. To date, the polymer flood has proceeded about as planned and although a definitive fieldwide response is not expected for another year, several wells have shown production response as well as a decreased saltwater cut.

Introduction

Polymer flooding can be an attractive candidate for achieving additional recovery from many reservoirs. Successful application of this technique depends upon many critical factors including reservoir properties and Flood design. Although many potential problems can be identified and resolved during the detailed project design phase, unanticipated and project design phase, unanticipated and unique challenges are always uncovered during field implementation. Several such challenges have been identified at the West Yellow Creek Field polymer flood, and, although problems remain, significant strides have been made in solving these operational difficulties.

FIELD DESCRIPTION

West Yellow Creek Field is located 170 miles (270 km) northeast of New Orleans, Louisiana, in Wayne County, Mississippi (see Figure 1). The field was discovered in 1947 and was initially developed by nine operators. The majority of the production in the field is from the Eutaw Oil Pool at approximately 4800 feet (1460 m) subsea.

The Eutaw Oil Pool is enclosed by a graben fault on the eastern side and an original oil-water contact on the west (see Figure 2). A deep-seated salt dome has splintered the productive area into three major fault blocks with ninety-two percent of current Eutaw production from the main fault block. Four sands comprise the Eutaw Pool. These are the Morrison, the First City Bank, the Second City Bank and the Stanley (see Figure 3).

Production rates from the Eutaw peaked in late 1950 at 3750 BOPD (596 m3/d), and by 1970 production had declined to 1100 BOPD (170 m3/d) (see Figure d). With reservoir pressure down to 500 psi (3 MPa) from an original pressure of 2000 psi (14 MPa), the potential pressure of 2000 psi (14 MPa), the potential for some type of secondary recovery process was evident. Subsequently, the Eutaw Pool was unitized in 1971, and Exxon was elected as operator.