Accurate knowledge about the subsurface structure and reservoir characteristics is essential to making informed decisions, optimizing production, and maximizing recovery.
Borehole imaging enables detailed visualization of complex structures, fracture networks, facies, and sedimentology. However, specialized expertise is required to correctly identify and classify geologic features, and to interpret their impact on the future productivity and economic viability of a well.
Cbm Coal Fracture Orientation In Vertical And Horizontal Wellbores From Electrical Images To Optimize Horizontal Well Placement
Nicole Lehocky and Jos Jonkers, Weatherford
Electrical images provide valuable geological and reservoir engineering information for reservoir characterization. In coalbed methane (CBM) applications, the orientation of the cleat system is used to determine the preferential direction for optimal placement of horizontal producers. Electrical images have proved to be reliable sources of information for determining the orientation of the coal cleat system from the vertical wellbores with subsequent placement of horizontal wellbores. The cleat system orientation and cleat intensity were verified from electrical images in the horizontal wellbores, and image analysis and interpretation resulted in calibrating these results to production rates. Static image normalization in the vertical wells was used as a benchmark to reference the images to the coal quality. Subsequently, the same static normalization technique was used in the horizontal section to estimate the coal quality. Certain conductive features were observed on the electrical images, and these were subsequently tied into conductive minerals from the core. The cross-sectional area of the image data was considerably larger than that of the core data; therefore the electrical images identified the cleat system in a superior way. The comparison of core to electrical image determined that image cleat-system interpretation is providing a minimum cleat intensity answer compared to core data. Image data were unable to resolve the very fine micro cleat systems that were evident from the core.
Weatherford borehole imaging technology delivers exceptional resolution with unrivaled versatility in deployment methods, which enables logging in otherwise impossible situations.
Armed with this logging data, our geologists identify structural features such as regional dip, folds, faults, and unconformities, and reveal the true nature of the subsurface structure, trap, and reservoir.
We also classify small-scale sedimentological features, including bedding, crossbedding, thin beds, and scour surfaces. Then our geologists identify and determine paleocurrent direction, generate accurate sand counts in thinly laminated or lenticular sands, and perform facies analysis to characterize the depositional environment.
The extensive knowledge and experience of our geoscientists enable us to offer complex services ranging from new patented processing techniques to sophisticated interpretation workflows and detailed geologic evaluation.
Our approximately 100 geoscientists are located throughout the world to accommodate clients.
We offer diverse geological interpretation services:
- Reveal 360™ image processing
- Depositional and stratigraphic interpretation
- Fracture and fault characterization
- Facies analysis
- Structural characterization
- Paleocurrent analysis
- Image petrophysics porosity analysis
- Sand-spectrum textural analysis
- Sand count and thin bed analysis
- In-situ stress analysis
- Core photo integration
Other imaging tools only let you see 50 to 70% of your wellbore, but Reveal 360 image processing gives you a complete, 360° picture of your wellbore regardless of bit size.
Our patented image processing technique reconstructs gaps in wireline logging images by replacing missing data with values consistent with the structural and textural information in the measured parts of the image. Even in clastic rock formations with a wide variety of sedimentary and structural features, the technique produces images that are nearly identical to full-coverage images.
An integrated solution based on unique reservoir characteristics, our FracAdvisor™ service provides near-real-time guidance for enhanced completion decision making. Capturing high-resolution borehole images and accurately interpreting these images are critical for calculating fracability along horizontal or vertical wellbores, fields, or basins. This knowledge helps to identify and stimulate sweet spots, and to optimize stage design and cluster placement in structurally complex geological environments.