Status of the Steam Drive Pilot in the Georgsdorf Field, Federal Republic of Germany
Authors: Lillie Wilhelm H.E. , Springer Friedrich P. 
Published: December 2007

This paper presents 4 years of experience from a steam drive pilot test in the Georgsdorf field, West Germany. It provides measurements of vertical heat movement in the reservoir as well as increases in hydrogen sulfide and carbon dioxide content in the produced solution gas.

Introduction

In 1979, approximately 3.6% of the annual demand for crude oil in the Federal Republic of Germany (FRG) was met by production from domestic oil fields. The annual demand for crude oil and refined products has been about 965 × 10(6) bbl (153 × 10(6) m3). About 23% of the domestic production came from the heavy-oil fields in the Emsland area.The Emsland area is located in the northwestern part of Germany and contains major fields such as Ruhlermoor, Georgsdorf, Emlichheim, and Ruhlertwist (Fig. 1). The latter two fields adjoin the Dutch border. Collectively, these fields account for almost one-half of the current reserves in the FRG, which are established to be about 464 × 10(6) bbl (73.8 × 10(6) m3).Recoveries and estimated remaining reserves (15% recovery and 13% proven and unproven reserves) are relatively low in the fields noted above. Accordingly, all companies operating in this area are keenly interested in improving production rates and recovery levels through the application of enhanced oil recovery methods. Based on current understandings, it is likely that at least another 11% of the original oil in place can be recovered through the use of thermal methods.A detailed petrophysical and reservoir engineering analysis of these fields, their responses to secondary recovery schemes (flank water drive and pattern flooding), and the motivation for applying heat to improve oil recovery were presented by Lubben.In 1960, a steam drive project was started in the Schoonebeek field in The Netherlands. The performances and the results of this test were reported by van Dijk.In the FRG, thermal activity started in 1966 when a few wells were steam stimulated on a trial basis. Following the results of these tests, Wintershall A.G. performed some 95 additional steam treatments in the Emlichheim field from 1966 to 1970. In 1967, Wintershall A.G. also started a massive hot-water injection project in the same field.

Georgsdorf Field

Georgsdorf was discovered in 1943 and was developed from 1946 to 1963 by drilling some 350 wells. BEB operates the field. Partners in the venture include C. Deilmann A.G., Preussag A.G., and Wintershall A.G. with each company owning 25%.The Georgsdorf structure is an east/west-trending asymmetric anticline with a steeply dipping north flank and a more gently dipping south flank (Fig. 2). The productive horizon is the Valanginian sandstone of Lower Cretaceous age. This sandstone has a net thickness that ranges from 100 to 260 ft (30 to 80 m) and permeabilities that vary between 100 and 1,800 md.In the north, west, and south, the reservoir is surrounded by an aquifer of significant size. In the east, the reservoir is limited by a facies change (shaleout). Major east/west faulting divides the reservoir into several nearly isolated fault blocks. Complementary faults further complicate reservoir description. The depth of the reservoir ranges from 1,500 ft (450 m) at its crest to 3,600 ft (1100 m) at the oil/water contact.

JPT

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