Evaluation of Water Saturation in a Low-Resistivity Pay Carbonate Reservoir Onshore Abu Dhabi: An Integrated Approach

2015 ◽  
Author(s):  
Miho Uchida ◽  
Andi Ahmad Salahuddin ◽  
Ayham Ashqar ◽  
Adedapo Noah Awolayo ◽  
Saheed Olawale Olayiwola ◽  
...  
Keyword(s):  
Water Saturation ◽  
Integrated Approach ◽  
Carbonate Reservoir ◽  
Abu Dhabi ◽  
Low Resistivity

scholarly journals A cohesive approach at estimating water saturation in a low-resistivity pay carbonate reservoir and its validation

2017 ◽  
Vol 7 (3) ◽  
pp. 637-657 ◽  
Author(s):  
Adedapo Awolayo ◽  
Ayham Ashqar ◽  
Miho Uchida ◽  
Andi Ahmad Salahuddin ◽  
Saheed Olawale Olayiwola
Keyword(s):  
Water Saturation ◽  
Carbonate Reservoir ◽  
Low Resistivity

scholarly journals Carbonate reservoir rock typing algorithm based on integrated approach (IRT)

2021 ◽  
Vol 6 (4) ◽  
pp. 62-70
Author(s):  
Mariia A. Kuntsevich ◽  
Sergey V. Kuznetsov ◽  
Igor V. Perevozkin
Keyword(s):  
Water Saturation ◽  
Integrated Approach ◽  
Learning Technologies ◽  
Carbonate Reservoir ◽  
Reservoir Rock ◽  
Static Properties ◽  
Reservoir Properties ◽  
Optimal Method ◽  
Rock Types ◽  
Rock Typing

The goal of carbonate rock typing is a realistic distribution of well data in a 3D model and the distribution of the corresponding rock types, on which the volume of hydrocarbon reserves and the dynamic characteristics of the flow will depend. Common rock typing approaches for carbonate rocks are based on texture, pore classification, electrofacies, or flow unit localization (FZI) and are often misleading because they based on sedimentation processes or mathematical justification. As a result, the identified rock types may poorly reflect the real distribution of reservoir rock characteristics. Materials and methods. The approach described in the work allows to eliminate such effects by identifying integrated rock types that control the static properties and dynamic behavior of the reservoir, while optimally linking with geological characteristics (diagenetic transformations, sedimentation features, as well as their union effect) and petrophysical characteristics (reservoir properties, relationship between the porosity and permeability, water saturation, radius of pore channels and others). The integrated algorithm consists of 8 steps, allowing the output to obtain rock-types in the maximum possible way connecting together all the characteristics of the rock, available initial information. The first test in the Middle East field confirmed the applicability of this technique. Results. The result of the work was the creation of a software product (certificate of state registration of the computer program “Lucia”, registration number 2021612075 dated 02/11/2021), which allows automating the process of identifying rock types in order to quickly select the most optimal method, as well as the possibility of their integration. As part of the product, machine learning technologies were introduced to predict rock types based on well logs in intervals not covered by coring studies, as well as in wells in which there is no coring.

Evaluating a Complex Low-Resistivity Pay Carbonate Reservoir Onshore Abu Dhabi: From Model to Implementation

2016 ◽  
Author(s):  
Ayham Ashqar ◽  
Miho Uchida ◽  
Andi A. Salahuddin ◽  
Saheed O. Olayiwola ◽  
Adedapo N. Awolayo
Keyword(s):  
Carbonate Reservoir ◽  
Abu Dhabi ◽  
Low Resistivity

Ultra-Deep Resistivity Mapping Tool Provided Geostopping Solution to Reduce Uncertainty and Eliminated the Need for Pilot Holes for the First Time Offshore Abu Dhabi

2021 ◽  
Author(s):  
Islam Khaled Moustafa ◽  
Freddy Alfonso Gutierrez ◽  
Ali Saeed Alfelasi ◽  
Hocine Khemissa ◽  
Omar Al Mutwali ◽  
...  
Keyword(s):  
Real Time ◽  
Water Saturation ◽  
Firing Frequency ◽  
Abu Dhabi ◽  
Target Zones ◽  
The Real ◽  
Pilot Hole ◽  
Low Resistivity ◽  
Mapping Tool ◽  
The Future

Abstract Drilling horizontal wells in the mature giant carbonate fields offshore Abu Dhabi, where high uncertainty regarding the lateral distribution of fluids results in variable water saturation, is very challenging. In order to meet the challenges and reduce uncertainty, the plan was to drill pilot holes to evaluate the resistivity of the target zones and plan horizontal sections based on the information gained. To investigate the possibility of avoiding pilot holes in the future, an ultra-deep electromagnetic (EM) tool was deployed to map the mature reservoirs, identifying formation and fluid boundaries before penetrating them, avoiding the need for pilot holes. Prewell inversion modeling was conducted to optimize the spacing and firing frequency selection and to facilitate early real-time geosteering and geostopping decisions. The plan was to run the ultra-deep resistivity mapping tool in conjunction with shallow propagation resistivity, density, and neutron porosity while drilling the 8 ½-in. landing section. The real-time ultra-deep EM inversion was run using depth of inversions up to 120 ft., to be able to detect the reservoir early and evaluate the predicted reservoir resistivity. This would allow optimization of any geostopping decision. The ultra-deep EM tool delivered accurate mapping of thin reservoir layers while drilling the 8 ½ inch section, as well as enhanced mapping of low resistivity zones up to 85 ft. True Vertical Thickness (TVT) in a challenging low resistivity environment. The real-time EM inversion enabled the prediction of resistivity values in target zones prior to entering the reservoir; values were later crosschecked against open-hole logs for validation. The results enabled identification of the optimal geostopping point in the 8 ½-in. section, enabling up to seven rig days to be saved in the future by eliminating pilot holes, in addition to eliminating the risk of setting a whipstock at high inclination with subsequent milling operations. In specific cases, this minimizes drilling risks in unknown/high reservoir pressure zones by improving early detection of a formation tops, thus improving geostopping decisions. Plans were modified for a nearby future well and the pilot-hole phase was eliminated because of the confidence provided by these results. Deployment of the ultra-deep EM tool in these mature carbonate reservoirs may reduce the uncertainty associated with fluid migration. In addition, use of the tool can facilitate precise geosteering to maintain distance from fluid boundaries in thick reservoirs. Furthermore, due to the depths of investigation possible with these tools, it will help enable the mapping of nearby reservoirs for future development. Further multi-disciplinary studies remain desirable using existing standard log data to validate the effectiveness of this concept for different fields and reservoirs.

An Integrated Approach for a Full-Field Optimized Development of a Carbonate Reservoir on a Shallow Marine Environment, Abu Dhabi

2007 ◽  
Author(s):  
Ahmed El Mahdi ◽  
Mohammed Ramadan Ayoub ◽  
Samy Daif-Allah ◽  
Shahin Negahban ◽  
Jamal Nasir Bahamaish ◽  
...  
Keyword(s):  
Marine Environment ◽  
Integrated Approach ◽  
Carbonate Reservoir ◽  
Abu Dhabi ◽  
Full Field ◽  
Shallow Marine ◽  
Shallow Marine Environment

Simulation of Miscible Displacement in Full-Diameter Carbonate Cores

1982 ◽  
Vol 22 (05) ◽  
pp. 647-657 ◽  
Author(s):  
J.P. Batycky ◽  
B.B. Maini ◽  
D.B. Fisher
Keyword(s):  
Oil Recovery ◽  
Water Saturation ◽  
Accurate Determination ◽  
Miscible Displacement ◽  
Carbonate Reservoir ◽  
Core Material ◽  
Immiscible Fluid ◽  
Displacement Efficiency ◽  
Carbonate Cores ◽  
Capacitance Model

Abstract Miscible gas displacement data obtained from full-diameter carbonate reservoir cores have been fitted to a modified miscible flow dispersion-capacitance model. Starting with earlier approaches, we have synthesized an algorithm that provides rapid and accurate determination of the three parameters included in the model: the dispersion coefficient, the flowing fraction of displaceable volume, and the rate constant for mass transfer between flowing and stagnant volumes. Quality of fit is verified with a finite-difference simulation. The dependencies of the three parameters have been evaluated as functions of the displacement velocity and of the water saturation within four carbonate cores composed of various amounts of matrix, vug, and fracture porosity. Numerical simulation of a composite core made by stacking three of the individual cores has been compared with the experimental data. For comparison, an analysis of Berea sandstone gas displacement also has been provided. Although the sandstone displays a minor dependence of gas recovery on water saturation, we found that the carbonate cores are strongly affected by water content. Such behavior would not be measurable if small carbonate samples that can reflect only matrix properties were used. This study therefore represents a significant assessment of the dispersion-capacitance model for carbonate cores and its ability to reflect changes in pore interconnectivity that accompany water saturation alteration. Introduction Miscible displacement processes are used widely in various aspects of oil recovery. A solvent slug injected into a reservoir can be used to displace miscibly either oil or gas. The necessary slug size is determined by the rate at which deterioration can occur as the slug is Another commonly used miscible process involves addition of a small slug within the injected fluids or gases to determine the nature and extent of inter well communication. The quantity of tracer material used is dictated by analytical detection capabilities and by an understanding of the miscible displacement properties of the reservoir. We can develop such understanding by performing one-dimensional (1D) step-change miscible displacement experiments within the laboratory with selected reservoir core material. The effluent profiles derived from the experiments then are fitted to a suitable mathematical model to express the behavior of each rock type through the use of a relatively small number of parameters. This paper illustrates the efficient application of the three-parameter, dispersion-capacitance model. Its application previously has been limited to use with small homogeneous plugs normally composed of intergranular and intencrystalline porosity, and its suitability for use with cores displaying macroscopic heterogeneity has been questioned. Consequently, in addition to illustrating its use with a homogeneous sandstone, we fit data derived from previously reported full-diameter carbonate cores. As noted earlier, these cores were heterogeneous, and each of them displayed different dual or multiple types of porosity characteristic of vugular and fractured carbonate rocks. Dispersion-Capacitance Model The displacement efficiency of one fluid by a second immiscible fluid within a porous medium depends on the complexity of rock and fluid properties. SPEJ P. 647^

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