An Experimental Investigation of Stress And Saturation Distribution on Porosity, Permeability and Geomechanical Properties of Najmah Kerogen, Sabriyah Field, North Kuwait for Field Development
The Sabriyah field is one of the largest producing fields in Kuwait. It is dominated by carbonate rocks in North Kuwait. The Najmah Formation is considered the hydrocarbon source for most of Sabriyah field reservoirs until the unconventional reservoirs have been introduced in Kuwait. The production from Najmah Formation has not begun yet. However, the field has a high production potential from the excellent total organic content (TOC) that ranges from 2.13-30.5 wt.% with an average of 8.3 wt.% and a vitrinite reflectance (Ro) of 1.28-6.6% (Khan et al., 2014). There have been many studies on Najmah formation as a source rock, yet studies as an unconventional reservoir rock for oil production is still rather recent and is ongoing. A reservoir characterization study has been conducted by Al-Qaod (2017) using core petrographic thin section analysis of Field Emission Scanning Electron Microscope (FESEM), X-Ray diffraction (XRD), X-Ray Fluorescence (XRF), source rock geochemistry for TOC, mercury injection capillary pressure (MICP) and nitrogen adsorption measurements, These analyses were integrated to determine the pore size distribution of the samples studied. This dissertation research will be a continuation of the prior reservoir characterization study to integrate the role of saturation distribution and in situ stress state on the geomechanical and petrophysical properties of the Najmah formation. High resolution 400 MHz NMR laboratory measurements will be conducted and the high resolution NMR results will be compared to low resolution 2 MHz as well as the field measurements. Geomechanical core measurements will also be introduced to determine the level of anisotropy in the rock properties and their variations with stress. The The petrophysical properties are affected by the stress state and These variations takes place as a result of the changes in the burial depth of the formation, the stress changes encountered as a result of the convergence and the divergence of the plate tectonics during the depositional history of the formations. Once the drilling and completions are completed and production starts, the local stress also changes as a function of time studying the geomechanical properties of the Najmah formation through tri-axial core measurements utilizing UNGI Integrated Geomechanics Laboratory will provide better understanding on the heterogeneity and direction dependence (anisotropy) of the petrophysical and geomechanical properties under in situ reservoir conditions and will enable the engineers to design proper well plan to initiate production from the Najmah formation as an unconventional reservoir prospect. Experiments will be conducted using core plugs drilled at various angles with respect to the bedding in dry and saturated conditions to study the impact of anisotropy on the reservoir properties. Hence, this research study will focus on the petrophysical and geomechanical properties of Najmah source rock variations as a function stress for for optimal well design and field development and recommendation of ideal well placement in the guidance of integrated dataset driven static model utilizing seismic, well logs, geomechanical, geochemical and petrophysical core measurements. This research will help delineate the different properties of Najmah Kerogen and its permeability association that will pave the way for the development of unconventional resources in Kuwait.
AAPG Datapages/Search and Discovery Article #90351 © 2019 AAPG Foundation 2019 Grants-in-Aid Projects