scholarly journals Characterization of flow units, rock and pore types for Mishrif Reservoir in West Qurna oilfield, Southern Iraq by using lithofacies data

2021 ◽  
Vol 11 (11) ◽  
pp. 4005-4018
Author(s):  
Ahmed N. Al-Dujaili ◽  
Mehdi Shabani ◽  
Mohammed S. AL-Jawad

AbstractThis study has been accomplished by testing three different models to determine rocks type, pore throat radius, and flow units for Mishrif Formation in West Qurna oilfield in Southern Iraq based on Mishrif full diameter cores from 20 wells. The three models that were used in this study were Lucia rocks type classification, Winland plot was utilized to determine the pore throat radius depending on the mercury injection test (r35), and (FZI) concepts to identify flow units which enabled us to recognize the differences between Mishrif units in these three categories. The study of pore characteristics is very significant in reservoir evaluation. It controls the storage mechanism and reservoir fluid properties of the permeable units while pore structure is a critical controlling factor for the petrophysical properties and multiphase-flow characteristics in reservoir rocks. Flow zone indicator (FZI) has been used to identify the hydraulic flow units approach (HFUs). Each (HFU) was reproduced by certain FZI and was supposed to have similar geological and petrophysical properties. The samples were from four lithofacies, mA, CRII, mB1, and mB2. Because of the wide range of cored-wells samples (20 wells), this paper is updated the previous studies and indicated some differences in the resulting categories. It was noticed as results of this study that the rocks types of the lower Mishrif were mostly ranged from wackestone to packstone in the upper part of mB2 which reflected mid-ramp facies while the upper part of mB2 referred to shoal facies and for the mB1 unit the rocks types mostly range from packstone to grainstone with some points as wackestone marked as shoal and rudist bioherm facies. Grainstone relatively decreases with the increasing of depth from upper to lower Mishrif while wackestone and packstone indicated increasing in the same direction. The unit mA is marked as mesopores and macropores, while megapores and macropores feature increased in mB1 which has been noticed in the northern part of West Qurna oilfield due to increasing shoal and rudist bioherm facies, the mB2 unit revealed increasing in mesoporous and decreasing in megaporous. The upper Mishrif (mA) has three flow units, while the lower Mishrif (mB1, mB2) has eight flow units four for each reservoir unit.

2013 ◽  
Vol 395-396 ◽  
pp. 230-233
Author(s):  
Qing Guo Zhang ◽  
Lu Lu Sun ◽  
Xi Chen

The determination of the physical property cutoffs of the effective reservoirs is a major factor that affects the result of the reserve calculation and is a difficult problem in the research of the reservoir evaluation. It is related to the exploration, development and decision-making. This paper used the empirical statistical method, the minimum pore throat radius method, the oil attitude method and the porosity permeability cross plot method to exploratorily strike the physical property cutoffs of the effective reservoirs of Yaoyi Formation in Cha 48 zone. It was based on the actual situation of the data of cores, the well testing and the well logging and combined with the applicability of various methods. The results achieve the attest of the data from the well testing and the producing test and provide the basis for the reservoir calculation.


2019 ◽  
Vol 13 (1) ◽  
pp. 97-113 ◽  
Author(s):  
Annan Boah Evans ◽  
Aidoo Borsah Abraham ◽  
Brantson Eric Thompson

Introduction: An improved understanding of complex clastic reservoirs has led to more detailed reservoir description using integrated approach. In this study, we implemented cluster analysis, geostatistical methods, reservoir quality indicator technique and reservoir simulation to characterize clastic system with complex pore architecture and heterogeneity. Methods: Model based clustering technique from Ward’s analytical algorithm was utilised to transform relationship between core and calculated well logs for paraflow units (PFUs) classification in terms of porosity, permeability and pore throat radius of the reservoir. The architecture of the reservoir at pore scale is described using flow zone indicator (FZI) values and the significant flow units characterized adopting the reservoir quality index (RQI) method. The reservoir porosity, permeability, oil saturation and pressure for delineated flow units were distributed stochastically in 2D numerical models utilising geostatistical conditional simulation. In addition, production behaviour of the field is predicted using history matching. Dynamic models were built for field water cut (FWCT), total field water production (FWPT) and field gas-oil-ratio (FGOR) and history matched, considering a number of simulation runs. Results: Results obtained showed a satisfactory match between the proposed models and history data, describing the production behaviour of the field. The average FWCT peaked at 78.9% with FWPT of 10 MMSTB. Consequently, high FGOR of 6.8 MSCF/STB was obtained. Conclusion: The integrated reservoir characterisation approach used in this study has provided the framework for defining productive zones and a better understanding of flow characteristics including spatial distribution of continuous and discrete reservoir properties for performance prediction of sandstone reservoir.


2012 ◽  
Vol 52 (2) ◽  
pp. 694
Author(s):  
Alexandra Golab ◽  
Mark Knackstedt ◽  
Thomas McKay ◽  
C Ward ◽  
Val Pinczewski

CSCSG reservoirs are intrinsically heterogeneous on every scale and the permeability and producibility of CSG is decreased when the pores and fractures are filled with minerals. The 3D characterisation and quantification of pore connectivity, cleat/fracture aperture and spacing, and extent of mineral infilling in coal is required for CSG reservoir evaluation of gas storage and flow characteristics. A technique has been developed to determine petrophysical properties of coal using data from a large-field, 3D microfocus X-ray computed tomography (µCT) at multiple scales, combined with SEM imaging, and automated mineralogy by QEMSCAN. µCT is a non-destructive technique and the X-ray densities of coal components are distinct; therefore, the pore/fracture, mineral, and coal matrix can be differentiated and quantified in 3D. The high resolution 3D image data can then be used to measure petrophysical properties. Specifically, this technique characterises porosity and its connectivity, cleat/fracture networks (aperture and spacing), cleat/fracture permeability, and mineral occurrences in 3D to better describe CSG reservoirs. The technique has been tested on samples of bituminous coal from a number of coalfields in the Sydney and Bowen Basins, Australia. The samples imaged were from 110–114 mm in diameter, yielding voxels ranging from 54–63 µm in size. The results can determine the depositional and post-depositional history of coal seams, in coal preparation and use, and in seam gas studies.


2019 ◽  
Vol 35 (8) ◽  
pp. 879-915 ◽  
Author(s):  
Bona Lu ◽  
Yan Niu ◽  
Feiguo Chen ◽  
Nouman Ahmad ◽  
Wei Wang ◽  
...  

Abstract Gas-solid fluidization is intrinsically dynamic and manifests mesoscale structures spanning a wide range of length and timescales. When involved with reactions, more complex phenomena emerge and thus pose bigger challenges for modeling. As the mesoscale is critical to understand multiphase reactive flows, which the conventional two-fluid model without mesoscale modeling may be inadequate to resolve even using extremely fine grids, this review attempts to demonstrate that the energy-minimization multiscale (EMMS) model could be a starting point to develop such mesoscale modeling. Then, the EMMS-based mesoscale modeling with emphasis on formulation of drag coefficients for different fluidization regimes, modification of mass transfer coefficient, and other extensions are discussed in an attempt to resolve the emerging challenges. Its applications with examples of development of novel fluid catalytic cracking and methanol-to-olefins processes prove that the mesoscale modeling plays a remarkable role in improving the predictions in hydrodynamic behaviors and overall reaction rate. However, the product content primarily depends on the chemical kinetic model itself, suggesting the necessity of an effective coupling between chemical kinetics and flow characteristics. The mesoscale modeling can be believed to accelerate the traditional experimental-based scale-up process with much lower cost in the future.


2017 ◽  
Vol 157 ◽  
pp. 941-950 ◽  
Author(s):  
Amir Maher Sayed Lala ◽  
Nahla A.A. El-Sayed
Keyword(s):  

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Fengjuan Dong ◽  
Xuefei Lu ◽  
Yuan Cao ◽  
Xinjiu Rao ◽  
Zeyong Sun

Tight sandstone reservoirs have small pore throat sizes and complex pore structures. Taking the Chang 6 tight sandstone reservoir in the Huaqing area of the Ordos Basin as an example, based on casting thin sections, nuclear magnetic resonance experiments, and modal analysis of pore size distribution characteristics, the Chang 6 tight sandstone reservoir in the study area can be divided into two types: wide bimodal mode reservoirs and asymmetric bimodal mode reservoirs. Based on the information entropy theory, the concept of “the entropy of microscale pore throats” is proposed to characterize the microscale pore throat differentiation of different reservoirs, and its influence on the distribution of movable fluid is discussed. There were significant differences in the entropy of the pore throat radius at different scales, which were mainly shown as follows: the entropy of the pore throat radius of 0.01~0.1 μm, >0.1 μm, and <0.01 μm decreased successively; that is, the complexity of the pore throat structure decreased successively. The correlation between the number of movable fluid occurrences on different scales of pore throats and the entropy of microscale pore throats in different reservoirs is also different, which is mainly shown as follows: in the intervals of >0.1 μm and 0.01~0.1 μm, the positive correlation between the occurrence quantity of movable fluid in the wide bimodal mode reservoir is better than that in the asymmetric bimodal mode reservoir. However, there was a negative correlation between the entropy of the pore throat radius and the number of fluid occurrences in the two types of reservoirs in the pore throat radius of <0.01 μm. Therefore, pore throats of >0.1 μm and 0.01~0.1 μm play a controlling role in studying the complexity of the microscopic pore throat structure and the distribution of movable fluid in the Chang 6 tight sandstone reservoir. The above results deepen the understanding of the pore throat structure of tight sandstone reservoirs and present guiding significance for classification evaluation, quantitative characterization, and efficient development of tight sandstone reservoirs.


2020 ◽  
Vol 6 (6) ◽  
pp. 1074-1090
Author(s):  
Nassrin Jassim Hussien Al-Mansori ◽  
Laith Shaker Ashoor Al-Zubaidi

Forecasting techniques are essential in the planning, design, and management of water resource systems. The numerical model introduced in this study turns governing differential equations into systems of linear or non-linear equations in the flow field, thereby revealing solutions. This one-dimensional hydrodynamic model represents the varied unsteady flow found in natural channels based on the Saint-Venant Equations. The model consists of the equations for the conservation of mass and momentum, which are recognized as very powerful mathematical tools for studying an important class of water resource problems. These problems are characterized by time dependence of flow and cover a wide range of phenomena. The formulations, held up by the four-point implicit finite difference scheme, solve the nonlinear system of equations using the Newton-Raphson iteration method with a modified Gaussian elimination technique. The model is calibrated using data on the Euphrates River during the early spring flood in 2015. It is verified by its application to an ideal canal and to the reach selected at the Euphrates River; this application is also used to predict the effect of hydraulic parameters on the river’s flow characteristics. A comparison between model results and field data indicates the feasibility of our technique and the accuracy of results (R2 = 0.997), meaning that the model is ready for future application whenever field observations are available. 


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