3D MODELING TO OPTIMIZE PRODUCTION AT THE SUCCESSIVE STAGES OF FIELD LIFE

Production optimization requires a clear understanding of subsurface c onditions throughout the field's life. Description of the subsurface t hrough classical 2D techniques is being replaced increasingly by power ful computer technology. Such technology enables construction of fully numeric 3D models of the subsurface, which can be visualized through high-end graphics displays. This 3D modeling technology is having a si gnificant impact on development planning and monitoring activities. Th e focus here is on the perceived benefits and challenges of using 3D m odels to optimize production. The paper includes examples of integrate d 3D static and dynamic modeling activities carried out on fields unde rgoing appraisal and development and fields facing abandonment. Case 1 (appraisal) illustrates how the integrated use of 3D static and dynam ic modeling during primary development enables petroleum engineers (PE 's) to construct alternative reservoir models rapidly and to evaluate the impact of various uncertainties quantitatively. This approach opti mizes production by facilitating fast-track developments, design of ro bust development schemes incorporating optimized well paths, and provi ding quantified justification for appraisal expenditure. Case 2 (mid f ield life) illustrates the benefits of using 3D modeling technology to integrate static and dynamic field data, geological knowledge, and sc enario analysis concepts to locate bypassed oil and optimize infill we ll trajectories. History matching offers the geologist valuable feedba ck on the robustness of the geological model, including aspects such a s the size and orientation of reservoir sands. The relative impact of various uncertainties can be quantified and development schemes optimi zed. Case 3 (end field life) illustrates how. even in very mature fiel ds that are facing abandonment, 3D modeling technology can facilitate data integration with subsequent cross-discipline interpretation. This leads to the successful planning and drilling of horizontal sidetrack s to develop bypassed oil. In all cases, the technology used allows so phisticated 3D models of the subsurface to be built through integratio n of diverse data types and geological knowledge. The resultant models can be upscaled rapidly for dynamic simulation; model optimization th rough iterative feedback from the reservoir flow simulator can be achi eved easily. The facility to plan and ''drill'' wells in the 3D volume enables development scenarios to be optimized both in terms of well t rajectory and multidisciplinary teamwork.