Improve reservoir delineation accuracy

Reliance Industries Limited was grappling with the tedious, time-consuming task of identifying boundaries of a complicated channel-levee system located in the KG basin, which covers the deltaic and interdeltaic areas of the Krishna and Godavari rivers and extends offshore along India’s east coast. The company wanted to not only extract the over-bank reservoir boundaries, but also establish a lateral and vertical connection of geobodies within the entire system. This would require a thorough demarcation of areas where continuous stratigraphic objects exist, including the channel-levee complex, delta areas, and channel bars.

Previously, Reliance had exclusively used aerial demarcation techniques that resulted in variations and did not provide accurate maps of the channel’s depth. Although legacy software was used to pick geobodies, they could not be converted onto true 3D grids, and were therefore not incorporated in the reservoir model. Actual reserves were difficult to estimate based on the existing workflow. A new approach was needed to capture the exact vertical extension of the channel-levee complex to delineate the reservoir and estimate reserves more accurately.

Improvements over past constraints

Another benefit of the Petrel software was its ability to incorporate data from various independent analyses. Specifically, the team was able to include a detailed thin bed characterization and petrophysical analysis results from core data in their reservoir model. Furthermore, probe alignment along the channel dip made it possible for the team to identify and demarcate the channel more accurately. Finally, the integrated approach of geobody picking and modeling enabled both facies and reservoir property modeling in the picked geobodies. These were all major improvements over previous modeling and geobody processing constraints.

Increased confidence in reserve estimates

The Petrel geobody extraction tool worked as planned and in a more efficient manner— taking only about one-fifth of the time typically required for such a complex job. Reliance was able to obtain good-quality seismic data, model the reservoir, and compute reserve estimates with much greater confidence than before. With the combined help of Schlumberger experts and software technology, the KG basin reservoir was fully identified and demarcated, allowing accurate population of reservoir properties within the geological model. Future Reliance projects will also be able to use the newly developed geocellular modeling technique to efficiently build accurate models through integration of all geological, geophysical, and well data.

Schlumberger Information Solutions

Schlumberger Information Solutions (SIS) is an operating unit of Schlumberger that  provides software, information management, IT, and related services. SIS collaborates closely with oil and gas companies to solve today’s tough reservoir challenges with an open business approach and comprehensive solution deployment. Through our technologies and services, oil and gas companies empower their people to improve business performance  by reducing exploration and development risk and optimizing operational efficiencies.

E-mail sisinfo@slb.com or contact your local Schlumberger representative to learn more.