Combining Proven Technologies into a Profitable Steamflood

The onshore Schoonebeek oilfield produced 25% of its 164 million m³ STOIIP from 1943 until 1996,<br>when exploitation was stopped, wells were abandoned and the surface infrastructure was removed. A 2003<br>study showed that the part of the field where the main drive mechanism was Solution Gas Drive is suitable<br>for redevelopment. The recovery factor in this area is 15%, which includes some recovery from water<br>injection and small-scale thermal EOR projects. Through 1960-1975 a successful small low-pressure<br>steam flood project with vertical wells was done in this area. Based on this success and the proven<br>suitability of horizontal wells in steam floods, a redevelopment was proposed using horizontal wells in a<br>low-pressure steam flood. However, the green-field state of the abandoned field made the threshold for<br>the investment decision high. Selection of proven technologies and rigorous handling of uncertainties led<br>to approval of the project and acceptance by the majority of third party stakeholders. Full field thermal<br>dynamic reservoir modeling was used to determine the optimal well placement. Full analysis of the project<br>sensitivity to subsurface uncertainties provided confidence in the predicted production performance. Use<br>of horizontal wells reduces the number wells and surface locations. Acquisition of high-resolution seismic<br>reduced structural uncertainty and detailed 3D static modeling helped well planning. Proven thermal well<br>completion technologies will be used, such as Limited Entry Perforations (LEPs) to ensure uniform steam<br>distribution in steam injectors. ROTAFLEX' long stroke rod pumps will be used to ensure that highly<br>productive wells produce at the required rates at high temperatures. A Combined Heat and Power plant<br>will generate steam and electricity efficiently, reducing the CO2 footprint. After treatment, oil will be<br>exported to a third party refinery in Lingen (Germany) and produced water will be injected into depleted<br>gas fields in the region. The 73 development wells will be campaign drilled beginning early 2009 using a<br>specially built rig.