Core-Log Integration across Crust-Mantle Transition in Oman
Abstract
With special interest on crust-mantle transitional changes and arrangements from Oman DP, drilling parameters were recorded at the wellsite to study the mechanical specific energy using the reference of core scratch tests, newly developed borehole magnetometer and most advanced geochemical logging technology were tested (Moe et al., 2018). Core characterization data from the Chikyu Oman Phase II (July-September, 2018) enables us to expand core-log integrated analyses, and types of the analyses and initial results will be presented.
Although drilling team tried to keep the hole open to the last minute, borehole walls collapsed at the deeper zone and reach of logging tools were limited, missing top boundary of paleo-Moho and mantle transition zone at CM1B. With the support from the Schlumberger Group President and team, logging operations were acquired in the best possible ways and hence data quality was excellent. All runs were made in full length of repeat sections as well as tried with different generation tools. Schlumberger's wireline logging acquired high-resolution and continuous density-porosity, natural and spectral gamma, resistivity and its images, sonic velocity (P & S waves), and geochemical logs (elements and minerals) in five runs to keep the toolstring shortest. Following the logging data audit procedure, borehole environmental correction, data quality check and depth matching as well as image data processing were carried out in JAMSTEC. Preliminary results matching well with core logging and core scratch tests, and resistivity, velocity, density, porosity and resistivity images were most distinctive to the rock types. Sharp changes between strong, relatively fresh layered gabbro and weak, serpentinized dunite and then moderately strong, Harzburgite, will be further analysed in fine scale across different measurements and compared with core logging data. Special analysis is verification of LithoScanner measured dry weigh elements with core XRF values, computing mineral volumetric fraction and formation porosity using petrophysical inversion application and then comparing with core XRD and porosity. Core-log-seismic integrated modeling on first site survey seismic data using industry application is also planned to have more information in drilling planning.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.V13E0141M
- Keywords:
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- 0456 Life in extreme environments;
- BIOGEOSCIENCESDE: 8140 Ophiolites;
- TECTONOPHYSICSDE: 8416 Mid-oceanic ridge processes;
- VOLCANOLOGYDE: 8424 Hydrothermal systems;
- VOLCANOLOGY