The study used the sedimentological and well log-based petrophysical analysis to evaluate the Farewell sandstone, the reservoir formation within the Kupe South Field. The sedimentological analysis was based on the data sets from Kupe South-1 to 5 wells, comprising the grain size, permeability, porosity, the total cement concentrations, and imprints of diagenetic processes on the reservoir formation. Moreover, well log analysis was carried on the four wells namely Kupe South 1, 2, 5 and 7 wells for evaluating the parameters e.g., shale volume, total and effective porosity, water wetness and hydrocarbon saturation, which influence the reservoir quality. The results from the sedimentological analysis demonstrated that the Farewell sandstone is compositionally varying from feldspathic arenite to lithic arenite. The analysis also showed the presence of significant total porosity and permeability fluctuating between 10.2 and 26.2% and 0.43–1376 mD, respectively. The diagenetic processes revealed the presence of authigenic clay and carbonate obstructing the pore spaces along with the occurrence of well-connected secondary and hybrid pores which eventually improved the reservoir quality of the Farewell sandstone. The well log analysis showed the presence of low shale volume between 10.9 and 29%, very good total and effective porosity values ranging from 19 to 32.3% as well as from 17 to 27%, respectively. The water saturation ranged from 22.3 to 44.9% and a significant hydrocarbon saturation fluctuating from 55.1 to 77.7% was also observed. The well log analysis also indicated the existence of nine hydrocarbon-bearing zones. The integrated findings from sedimentological and well log analyses verified the Farewell sandstone as a good reservoir formation.

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Reservoir quality evaluation of the Farewell sandstone by integrating sedimentological and well log analysis in the Kupe South Field, Taranaki Basin-New Zealand

Along with conventional methods, this paper proposed a method in which 1D and 3D models are integrated to identify the self-sourced reservoir potential of the Farewell Formation in the Kupe Gas Field within the Taranaki Basin, New Zealand. Source rock characteristics were evaluated at both field and basin scales by investigating source rock maturity, type of organic matter, and hydrocarbon generation potential by rock pyrolysis, using Rock-Eval 2 and 6. The 1D thermal and burial history model established the rate of sedimentation and thermal history of the Kupe 4 well. Reservoir characterization at field-scale was determined by seismic interpretation, well log analysis, and 3D structural and petrophysical models. The sediments of the Farewell Formation contain types II–III (oil/gas prone) and type III (gas prone) and have fair-to-excellent generation potential. The oxygen and hydrogen indices ranged from 3 to 476 mg CO2/g TOC and 26 to 356 mg HC/g TOC, respectively, whereas the thermal maturity determined by vitrinite reflectance values ranged between 0.3% and 0.72%, indicating that the Farewell Formation is in immature-to-mature hydrocarbon generation stage. Thus, Farewell Formation was verified to be a good source rock. Additionally, structural interpretations demonstrated the structural complexity of an extensional and contractional regime within the reservoir package. Multiple faults indicated a good reservoir property there with a trapping mechanism as well as migration paths. A well-log-based petrophysical analysis established the presence of up to 70% hydrocarbon saturation within the pore spaces of Farewell sandstones. The 3D models confirmed that the Farewell Formation has significant sand zones and hydrocarbon-saturated zones, thereby proving its very good reservoir characteristics. It has been proved that the 1D and 3D structural schemes, integrated with geological techniques, was vital in identifying the Kupe Field as a self-sourced reservoir.

Integration of 1D and 3D modeling schemes to establish the Farewell Formation as a self-sourced reservoir in Kupe Field, Taranaki Basin, New Zealand

Integrated wireline log and seismic attribute analysis for the reservoir evaluation: A case study of the Mount Messenger Formation in Kaimiro Field, Taranaki Basin, New Zealand

3D visualization of geological and geophysical data has been continuously developed in recent decades for better prediction and simulation of subsurface systems. 3D modeling has gained attention from interpreters as well as decisions makers in the energy sector. The integration of 3D structural, facies, petrophysical, and geomechanical models can be used to obtain more reliable estimates of gas in place in the conventional and unconventional gas reservoirs. As well, 3D geomechanical model can be used to expose the root cause of drilling difficulties in gas reservoir and development of gas reservoirs. This chapter seeks to introduce the workflow and 3D modeling procedures in gas reservoirs. It provides a case study of 3D structural, facies, petrophysical, and geomechanical modeling in a gas reservoir from the southern central, Gulf of Suez, Egypt. Banner headline Three-dimensional modeling and visualization of subsurface gas reservoirs is a critical industry practice, and its significance originates from its theoretical and application value in exploration, development, and production. When modeling the subsurface system in both conventional and unconventional resources, it is critical to take into account a large number of datasets. The more data entered into the model, the better the model's accuracy. The heterogeneity of the data, the time required for data handling, numerical storage and accessibility, and the reliability of geological information assessments could all be sources of uncertainty that impact the 3D modeling process, posing modeling challenges. Such 3D modeling challenges can be overcome with more integrated data, precise calibration, and core measurements, resulting in more precise models.

Three-dimensional gas property geological modeling and simulation

3D visualization of geological and geophysical data has been continuously developed in recent decades for better prediction and simulation of subsurface systems. 3D modeling has gained attention from interpreters as well as decisions makers in the energy sector. The integration of 3D structural, facies, petrophysical, and geomechanical models can be used to obtain more reliable estimates of gas in place in the conventional and unconventional gas reservoirs. As well, 3D geomechanical model can be used to expose the root cause of drilling difficulties in gas reservoir and development of gas reservoirs. This chapter seeks to introduce the workflow and 3D modeling procedures in gas reservoirs. It provides a case study of 3D structural, facies, petrophysical, and geomechanical modeling in a gas reservoir from the southern central, Gulf of Suez, Egypt. Banner headline Three-dimensional modeling and visualization of subsurface gas reservoirs is a critical industry practice, and its significance originates from its theoretical and application value in exploration, development, and production. When modeling the subsurface system in both conventional and unconventional resources, it is critical to take into account a large number of datasets. The more data entered into the model, the better the model's accuracy. The heterogeneity of the data, the time required for data handling, numerical storage and accessibility, and the reliability of geological information assessments could all be sources of uncertainty that impact the 3D modeling process, posing modeling challenges. Such 3D modeling challenges can be overcome with more integrated data, precise calibration, and core measurements, resulting in more precise models. 

This study integrated three-dimensional (3D) structural and petrophysical models to establish the reservoir characteristics of the Mangahewa Formation within the Pohokura Gas-Condensate Field. The 3D structural model, in which 3 horizons and 51 faults were interpreted, was developed using an algorithm for volume-based modeling. The complex structural mechanism was observed as compressional and extensional stresses resulting in steeply dipping normal and reverse faults. The fault throw was estimated to be up to 85 m, and 33% of the faults had throws of less than 10 m. This explains the fault growth system as small, younger faults have merged to develop larger faults. Well log analysis was used to evaluate important petrophysical parameters such as effective porosity, net-to-gross ratio, shale volume, and water and hydrocarbon saturation. After applying a cutoff, the estimated values for effective porosity, net-to-gross ratio, shale volume, and water and hydrocarbon saturation were 12–18%, 13–31%, 13–26%, 6–22%, and 78–94%, respectively. The estimated values were then incorporated into the grid cells to design 3D petrophysical modeling using the algorithm for sequential Gaussian simulation. The structural model indicated effective trapping and the presence of a conduit mechanism for hydrocarbons. The well log analysis identified significant effective porosities containing substantial hydrocarbon saturation, whereas the petrophysical models showed very good dissemination of the petrophysical parameters. From these models, which also incorporate the gas–water contact, proposed drilling sites for future exploration and well development were proposed. The results characterize the Mangahewa Formation as a good reservoir within the Pohokura Gas-Condensate Field.

Three-Dimensional Structural and Petrophysical Modeling for Reservoir Characterization of the Mangahewa Formation, Pohokura Gas-Condensate Field, Taranaki Basin, New Zealand

Geochemistry of recent and fossil brachiopod calcite of Megathiris detruncata (Terebratulida, Megathyrididae): A modern baseline study to trace past environmental conditions

Mutiah Yunsi

Papers

Three-Dimensional Structural and Petrophysical Modeling for Reservoir Characterization of the Mangahewa Formation, Pohokura Gas-Condensate Field, Taranaki Basin, New Zealand

Geochemistry of recent and fossil brachiopod calcite of Megathiris detruncata (Terebratulida, Megathyrididae): A modern baseline study to trace past environmental conditions