Abstract CS Resources has been a pioneer in the use of horizontal wells to develop heavy oil reservoirs. From 1988 to 1991, CS Resources drilled, and currently operates, 17 horizontal wells in a thin, heavy oil pool in the Pelican Lake area in northcentral Alberta. The horizontal wells were drilled in three phases; eight wells, in 1988, five wells in 1989/1990 and four wells in 1991. At each phase of development, well costs improved and productivities increased. The continual improvement in the overall performance and cost effectiveness of the project can be attributed to the focused approach CS Resources takes toward pool development. This paper will discuss the aforementioned phases of development and how knowledge gained from each phase was used to improve performance in subsequent phases. Several significant accomplishments will also be discussed, including:The drilling of the first ever lateral arm off of a horizontal well in Canada.The drilling of an experimental "J" type profile (in an attempt to improve pump performance).The drilling of a horizontal well with a horizontal length/vertical depth ratio believed to be greater than that of any other well ever drilled. Introduction Most of the vertical wells at Pelican Lake had been shut in due to uneconomical Production. In January 1988 when the first eight horizontal wells were drilled in Pelican Lake, Very few horizontal wells have been drilled in Canada. Some discussion of the first eight Well phase is given in References (1) and (2). Use of horizontal well technologies has turned the Project into a technical and economic success a success which can be attributed to CS Resources focused approach To pool development approach used us comprised of three key components:RESEARCH-Considerable technical work was completed prior to each phase of development.COMMITMENT-Some of the first wells drilled sis not perform as well as predicted. The reasons for the under performance were investigated and the project has since become a success.COMMUNICATION-Discussion throughout the project between geology, drilling, reservoir and production disciplines as well as field staff and service companies, has improved overall project understanding. It has also lead to continual cost and productivity improvements. History The Pelican Lake area is located 175 miles north of Edmonton, Alberta (Figure 1). The discovery well, Gulf Pelican 6-9-81-22W4, was drilled in 1978. The main oil bearing formation is the Wabiskaw "A" which has an average net oil pay of 5.0m. The PI gravity of the oil is 14', and the viscosity is between 600 and 100 centipoise at 20 ºC. Formation Sand has an average porosity of 26 and an average horizontal permeability of 3 darcies. During October 1987, CS Resources entered into a farm-out and option agreement with Gulf Canada covering 58 square miles in the Pelican Lake area. Prior to CS Resources acquisition of the subject lands, more than $100 million had been expended in the Pelican Lake area. From 1980 to 1986, approximately 100 vertical and deviated wells were drilled.