Location and background
The Guaduas field was a Pacific Stratus property and is located in the municipality of Guaduas in the department of Cundinamarca, 90 km northwest of Bogota, and is part of the Middle Magdalena Basin. Pacific Rubiales owns 90.6% of the participating interest in this sole risk contract entered into with Ecopetrol.
Geology
The Guaduas field is located in the Middle Magdalena Valley Basin on the east flank of the Guaduas syncline, created by the movement of the Honda thrust. Production is from the late Cretaceous Cimarrona Formation, which is a sequence of alternating clastic and carbonate rocks deposited in a transitional marine environment. The reservoir Cimarrona Formation, in the Guaduas field, is composed of fractured limestones and calcareous sandstones, interbedded with calcareous shales and siltstones. Development of the field is focused on fracturing of limestones and sands, drilling perpendicularly to the direction of the fractures in order to drain most of the hydrocarbons trapped within the fractures.
Production
During 2007 the company focused its efforts on maintaining production, which averaged 1,122 bbl/d, 6.3 MMcfd and 1,230 barrels of water per day, for a total production of 409,846 bbl of 18.5 API crude. Production came from nine active wells having an aggregate historical production of 10.1 Mmbbl.
Reserves
Net proved producing reserves at Guaduas consist of 1.313 Mmbbl and net non producing reserves are estimated to be 0.114 MMbbl. As well, there are estimated to be 1.271 MMbbl of proved undeveloped reserves and probable undeveloped reserves of 1.256 MMbbl. (Petrotech Engineering Ltd Report, December 31, 2007)
Other Uses
In 2007 the company conducted an analysis of how it could increase its return on investment in the Guaduas field, and identified two alternative uses to the traditional sale of crude from the field. The first consisted of utilizing idle storage and pumping capacity at the field by constructing facilities to receive a mix of heavy-light crude (from Rubiales Oil Field) in order to ultimately pump 20,000 bbl/d of oil per day of this blended crude. As well, beginning in November 2007, the PF1 production facilities at the field were adapted to receive 5,600 bbl/d, allowing the receipt, mixing and pumping of 125,169 bbl by year end.
The second use related to the sale of gas produced at the field; accordingly, a purchaser of 1.0 MMcf/d was identified and an agreement reached. Construction of the gas delivery facilities will be completed by April 2008.
