scholarly journals 3D geology and reservoir modeling in oil industry: Geologic model construction by integration of sedimentology, sequence stratigraphy, seismic geomorphology, exploration geophysics and geostatistics

2013 ◽  
Vol 119 (8) ◽  
pp. 567-579
Author(s):  
Osamu Takano ◽  
Takashi Tsuji
Keyword(s):  
Sequence Stratigraphy ◽  
Oil Industry ◽  
Model Construction ◽  
Reservoir Modeling ◽  
Seismic Geomorphology ◽  
Geologic Model

Unstructured Cut-Cell Grids for Modeling Complex Reservoirs

SPE Journal ◽  
2014 ◽  
Vol 19 (02) ◽  
pp. 340-352 ◽  
Author(s):  
Brad Mallison ◽  
Charles Sword ◽  
Thomas Viard ◽  
William Milliken ◽  
Amy Cheng
Keyword(s):  
Unstructured Grids ◽  
Simulation Models ◽  
Small Cells ◽  
Tetrahedral Mesh ◽  
Reservoir Modeling ◽  
Normal Faults ◽  
Numerical Representation ◽  
Cut Cell ◽  
Earth Models ◽  
Geologic Model

Summary Effective workflows for translating Earth models into simulation models require grids that preserve geologic accuracy, offer flexible resolution control, integrate tightly with upscaling, and can be generated easily. Corner-point grids and pillar-based unstructured grids fail to satisfy these objectives; hence, a truly 3D unstructured approach is required. This paper describes unstructured cut-cell gridding tools that address these needs and improve the integration of our overall reservoir-modeling workflows. The construction of simulation grids begins with the geologic model: a numerical representation of the reservoir structure, stratigraphy, and properties. Our gridding uses a geochronological (GeoChron) map from physical coordinates to an unfaulted and unfolded depositional coordinate system. The mapping is represented implicitly on a tetrahedral mesh that conforms to faults, and it facilitates accurate geostatistical modeling of static depositional properties. In the simplest use case, we create an explicit representation of the geologic model as an unstructured polyhedral grid. Away from faults and other discontinuities, the cells are hexahedral, highly orthogonal, and arranged in a structured manner. Geometric cutting operations create general polyhedra adjacent to faults and explicit contact polygons across faults. The conversion of implicit models to explicit grids is conceptually straightforward, but the implementation is nontrivial because of the limitations of finite precision arithmetic and the need to remove small cells formed in the cutting process. In practice, simulation grids are often constructed at coarser resolutions than Earth models. Our implementation of local grid coarsening and refinement exploits the flexibility of unstructured grids to minimize upscaling errors and to preserve critical geologic features. Because the simulation grid and the geologic model are constructed by use of the same mapping, fine cells can be nested exactly inside coarse cells. Therefore, flow-based upscaling can be applied efficiently without resampling onto temporary local grids. This paper describes algorithms and data structures for constructing, storing, and simulating cut-cell grids. Examples illustrate the accurate modeling of normal faults, y-faults, overturned layers, and complex stratigraphy. Flow results, including a field-sector model, show the suitability of cut-cell grids for simulation.

scholarly journals Stimulated Reservoir Volume Characterization and Optimum Lateral Well Spacing Study of Two-Well Pad: Midland Basin Case Study

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Jaeyoung Park ◽  
Candra Janova
Keyword(s):  
History Matching ◽  
Flow Simulation ◽  
Population Based ◽  
Reservoir Modeling ◽  
Target Area ◽  
Well Performance ◽  
Stimulated Reservoir Volume ◽  
Midland Basin ◽  
Well Spacing ◽  
Geologic Model

This paper introduces a flow simulation-based reservoir modeling study of a two-well pad with long production history and identical completion parameters in the Midland Basin. The study includes building geologic model, history matching, well performance prediction, and finding optimum lateral well spacing in terms of oil volume and economic metrics. The reservoir model was constructed based on a geologic model, integrating well logs, and core data near the target area. Next, a sensitivity analysis was performed on the reservoir simulation model to better understand influential parameters on simulation results. The following history matching was conducted with the satisfactory quality, less than 10% of global error, and after the model calibration ranges of history matching parameters have substantially reduced. The population-based history matching algorithm provides the ensemble of the history-matched model, and the top 50 history-matched models were selected to predict the range of Estimate Ultimate Recovery (EUR), showing that P50 of oil EUR is within the acceptable range of the deterministic EUR estimates. With the best history-matched model, we investigated lateral well spacing sensitivity of the pad in terms of the maximum recovery volume and economic benefit. The results show that, given the current completion design, the well spacing tighter than the current practice in the area is less effective regarding the oil volume recovery. However, economic metrics suggest that the additional monetary value can be realized with 150% of current development assumption. The presented workflow provides a systematic approach to find the optimum lateral well spacing in terms of volume and economic metrics per one section given economic assumptions, and the workflow can be readily repeated to evaluate spacing optimization in other acreage.

scholarly journals Specifying Quality of a Tight Oil Reservoir through 3-D Reservoir Modeling

2020 ◽  
pp. 3252-3265
Author(s):  
Nagham Jasim ◽  
Sameera M. Hamd-Allah ◽  
Hazim Abass
Keyword(s):  
History Matching ◽  
Simulation Models ◽  
Static Model ◽  
Model Construction ◽  
Reservoir Modeling ◽  
Oil Reservoir ◽  
Main Challenge ◽  
Static Modeling ◽  
Porosity And Permeability ◽  
Log Interpretation

Increasing hydrocarbon recovery from tight reservoirs is an essential goal of oil industry in the recent years. Building real dynamic simulation models and selecting and designing suitable development strategies for such reservoirs need basically to construct accurate structural static model construction. The uncertainties in building 3-D reservoir models are a real challenge for such micro to nano pore scale structure. Based on data from 24 wells distributed throughout the Sadi tight formation. An application of building a 3-D static model for a tight limestone oil reservoir in Iraq is presented in this study. The most common uncertainties confronted while building the model were illustrated. Such as accurate estimations of cut-off permeability and porosity values. These values directly affect the calculation of net pay thickness for each layer in the reservoir and consequently affect the target of estimating reservoir initial oil in place (IOIP). Also, the main challenge to the static modeling of such reservoirs is dealing with tight reservoir characteristics which cause major reservoir heterogeneity and complexities that are problematic to the process of modeling reservoir simulation. Twenty seven porosity and permeability measurements from Sadi/Tanuma reservoir were used to validate log interpretation data for model construction. The results of the history matching process of the constructed dynamic model is also presented in this paper, including data related to oil production, reservoir pressure, and well flowing pressure due to available production.

Seismic geomorphology linked to sequence stratigraphy of an Eocene delta in the Outer Moray Firth, UKCS

2019 ◽  
Vol 104 ◽  
pp. 150-167
Author(s):  
E.H. Zimmer ◽  
J.A. Howell ◽  
N. Schofield ◽  
R.L. Gawthorpe
Keyword(s):  
Sequence Stratigraphy ◽  
Seismic Geomorphology ◽  
Moray Firth

Integration of sequence stratigraphy and geostatistics in 3-D reservoir modeling: a case study of Otumara field, onshore Niger Delta

2015 ◽  
Vol 8 (10) ◽  
pp. 8615-8631 ◽  
Author(s):  
Paul Edigbue ◽  
Mary Taiwo Olowokere ◽  
Peter Adetokunbo ◽  
Eniolayimika Jegede
Keyword(s):  
Sequence Stratigraphy ◽  
Niger Delta ◽  
Reservoir Modeling
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