Abhijit Gangopadhyay

Multidisciplinary approach in determining the best zone to land a Haynesville horizontal well

AbstractThe Upper Jurassic Haynesville Shale Formation in the East Texas Basin, North America, is a black, organic-rich, calcareous mudstone that lies below the Bossier Shale and above the Cotton Valley Limestone. The reservoir quality was controlled by primary depositional process and secondary diagenesis. The best lithology type in terms of drilling, completion, and production is the organic-rich, silty calcareous mudstone with low clay content. The studied well traversed the entire Haynesville Formation with the objective to assess the production potential of this formation. We acquired open-hole, triple-combo logging while drilling (LWD) logs, two types of production logs, and regional microseismic data. Postdrill log modeling confirmed that the horizontal well stayed on the planned trajectory, based on the log correlation between the horizontal and offset wells. Log modeling demonstrated that the LWD resistivity logs in horizontal wells are subject to resistivity anisotropy and polarization horn effe...

Analysis and Interpretation of a 3D3C single sensor pilot dataset: East Texas Blocker Field Case Study

In 2009, BP acquired a 7 square mile 3D3C pilot dataset utilizing ION’s FireFly cableless acquisition system over BP’s East Texas Blocker Field. This acquisition delivered a high density, full azimuth, 3-component dataset that aided in the planning and execution of a full-field production survey over the field. Very careful processing was applied to the full wavefield pilot dataset to optimize resolution and retain robust amplitude and azimuthal information. In addition to conventional full stack seismic attributes, AVO (Amplitude with Offset) and AVOAz (AVO with Azimuth) attributes, and seismic inversion volumes and have been generated and analyzed. Learnings from the analysis of the pilot datasets are being used to optimize the interpretation and analysis workflows of larger, more recent East Texas production 3D datasets. .

Anisotropic Seismic Depth Migration to Aid Tight Gas Prospectivity In the Mountain Front Region of the Anadarko Basin

Summary We describe a seismic depth imaging workflow that helps delineate tight gas prospectivity in the Mountain Front area of the Anadarko basin in the mid-continent United States. Our workflow involves extensive pre-processing of the seismic data, pre-stack Kirchhoff time and depth migration incorporating appropriate velocity models, and accounts for local anisotropy. Compared to previously available time migrated seismic data from the Mountain Front region, the resulting depth migrated seismic data from the application of our workflow shows substantial improvement in revealing the complex structural geology of the region. Improved clarity of the subsurface image, particularly in the deeper areas around the Mountain Front, leads to improved interpretability of the data, and hence puts us in an advantageous position to generate prospects which in turn helps make sound business decisions. Our workflow also has the potential to serve as an example for evaluating tight gas prospectivity in a similar tectonic environment.