A B S T R A C TReservoir management studies of California's Kern River field rely on a full-field 155-million cell three-dimensional (3D) earth model. This full-field model provides input for reserves estimation as well as the identification, targeting, and ranking of remaining opportunities. The earth model is regarded as "fit for purpose" in that characteristics of the model are aligned with specific needs for reservoir management. Normalized resistivity logs from more than 12,000 wells are used to establish lithology and reservoir architecture. Temperature, steam, gas, and oil saturation logs from over 650 boreholes provide regular periodic surveillance for identifying changes in fluids and temperature. Changes in fluid contacts and saturations are integrated with reservoir architecture three times each year. These model updates are important to the development teams for staying current on changes in their project area. The integration of these data provides the basis for linked reserves and resource estimation and the identification and development of remaining opportunities. Kern River reserves and resources are estimated from the model for over 130 internal reporting entities. For asset reservoir management purposes, reserves are updated for over 160,000 entities (based on patterns, zones, and reserves) across the 12-sq-mi (31-sq-km) field. The updated reserves supply input to reserves distribution maps and spreadsheets used for evaluating workover and new development opportunities. Some of these opportunities represent heat mining of untapped hot oil zones whereas other opportunities are cold and require the introduction of steam to mobilize the oil. Using multiple reservoir property characteristics as filter criteria for identifying remaining opportunities is an important tool used at

No abstract

Gas or steam gravity drainage is a very efficient recovery mechanism. Field observations, laboratory studies and pore network modeling have pointed towards very low residual oil saturations and high recovery with gravity drainage. While work during the last three decades has focused on understanding the physics of three-phase flow, literature on field scale gravity drainage production decline characteristics is somewhat limited. Understanding field level production decline characteristics is important as it enables better production forecasting, resource estimation and reservoir management.In this paper production data from two fields under gravity drainage is evaluated and it shows strong exponential decline characteristics. After an initial period of rapid decline, there is a period of lower decline for a long period of time. The paper relates field scale observations of gravity drainage to laboratory observations of gravity drainage in long cores. The laboratory experiments show similar behaviors where a period of initial rapid decline is followed by a long period of lower decline, resulting in very low remaining oil saturation in the gas invaded zone. The paper discusses physics of gravity drainage displacement and summarizes similarities and differences between field and laboratory observations.

No abstract