- Home
- Conferences
- Conference Proceedings
- Conferences
76th EAGE Conference and Exhibition 2014
- Conference date: June 16-19, 2014
- Location: Amsterdam, Netherlands
- Published: 16 June 2014
1021 - 1028 of 1028 results
-
-
Investigation and Model Correlations of Vp/vs and Porosity of Carbonates
Authors J. Pupos and N. GegenhuberSummaryMany articles deal with the topic of compressional and shear wave velocity of carbonate rocks and their correlation as well as model correlations. This paper will show the first results of compressional and shear wave velocity measurements and the calculations using the model of Kuster & Toksoez. Different carbonates of Austria were measured in the laboratory to determine their porosity as well as their compressional and shear wave velocity (dry). Two different measurements were executed to determine the effective porosity of samples (helium porosity and principle of Archimedes). Some samples have bigger helium porosity than the porosity that derived using the buoyance method. It was assumed that there are more pores with a radius under the radius of a water molecule, while they are big enough to let a helium molecule through.
Using the measured compressional/shear wave velocity and the effective porosity the inclusion model that developed by Kuster and Toksoez was accomplished for the dry samples. This model is limited to low porosity our result was sufficient. The penny shaped cracks with different aspect ratio (0.005–0.5) were used. It was observed, that different aspect ratios needed to be applied for different lithologies.
-
-
-
High Resolution Stratigraphy and Reservoir Heterogeneity of Khartam Member of Khuff Formation from Outcrop, Saudi Arabia
Authors M. Osman, O. Abdullatif, M. Al-Farhan, H. Eltom and M. BashriSummaryThe Permian-Triassic Khuff Formation is the most prolific for natural gas production in the Middle East. Understanding the Khuff reservoir heterogeneity is important to enhance the hydrocarbon production. Integrated study including sedimentology, stratigraphy and digital outcrop modelling is applied here. The studied Upper Khartam Member outcrop is an analog for the Khuff-A reservoir in the subsurface. Ten lithofacies were identified from the whole samples collected from the outcrop. These lithofacies were interpreted to have been deposited in 1) marine transgression, 2) foreshoal, 3) shoal complex, 4) shoal fringes, 5) back shoal, 6) tidal flat and 7) supratidal flat. The composite sequences of the Upper Khartam Member consist of five high frequency sequences. The results of this study also showed a distinct five potential reservoir units in the second and third high frequency sequences. The digital modelling been applied to these sequences to delineate the reservoir units in a more realistic and high precision environment. Outcomes of this study can be utilized to decrease uncertainty on reservoir continuity and architecture and lateral facies continuity within interwell spacing in equivalent Khuff reservoir models in the subsurface. Consequently this might enhance understanding and prediction of reservoir quality in the subsurface.
-
-
-
Steady and Unsteady Flow in Permeable-fractured Carbonate Reservoirs
Authors L.C. Vasquez Cardenas and N.S. GolikovSummaryThis paper will discuss and suggest possible applications for the results of the aforementioned processes on a larger scale, utilizing systematical approaches with the scales of evaluation from core to reservoir, and adaptations for several hydrodynamic models. It also explains the impact of wettability and capillary forces during the drainage process between matrix and fractured structures. Furthermore, through the examination of pressure gradients, effective viscosities, and yield-shear stresses, a complete comprehension of reservoir dynamics will be greatly facilitated.
-
-
-
A Modelling Study Of Broadband Seismic Wave Propagation In A Deep Mine
Authors R. Saleh and B. MilkereitSummaryUnderstanding the propagation of seismic waves in a presence of very strong elastic contrasts, such as topography, tunnels and ore-bodies is still a challenge. Safety in mining is a major concern and seismic monitoring is the main tool here. For engineering purposes, amplitudes (peak particle velocity/acceleration) and travel times of seismic events (mostly blasts or microseismic events) are critical parameters that have to be determined at various locations in a mine. These parameters are useful in preparing risk maps or to better understand the process of spatial and temporal stress distributions in a mine. Simple constant velocity models used for mine monitoring, cannot explain the observed complexities in scattered seismic waves. In hard-rock environments modelling of elastic seismic wavefield require detailed 3D petrophysical, infrastructure and topographical data to simulate the propagation of seismic wave with a frequencies up to few kilohertz. In this study, the effects of strong elastic contrasts on the propagation of broadband seismic waves will be illustrated using 2D/3D finite difference method.
-
-
-
Steam Actuated In-Situ Combustion - An Advancement in EOR
By G. SinghSummaryIn-situ combustion (ISC) is used widely but with limited field success due to vast capital costs, operating expenses, flue gas emissions, water treatment and handling costs are associated with it. There is a need to optimize efficiency of recovery process by lowering air requirement, environmental impact, and costs of technique. As the principle recovery mechanisms for combination of steam and combustion processes are steam distillation, viscosity reduction and thermal expansion of oil. Therefore steam extracts lighter hydrocarbon fractions, so that the residue becomes heavier, mixing of distilled component with initial oil results in lighter produced oil. Thus the use of steam in combination with air reduces air requirement with low emission of flue gases during the process. Three important mechanism on which thermal recovery methods depends are thermal expansion, viscosity reduction and steam distillation.
Combustion tube run experiments were carried out to obtain the information about the reservoir and to find the combustion parameters. Combination of ISC and steam flooding increases the life of project and at the same time minimizes emission of flue gases during process and thus improves recovery.
-
-
-
Optimization of Polymer Flooding Design for Maximizing Economic Profit under Bottom-Water Condition
By K.H. ParkSummaryBottom-water aquifer has been considered as an unfavourable condition for polymer flooding. It causes the excessive water production which might cause the abandonment of the operation. A number of researches have focused on the identification and remediation of such problems. Among suggested solutions, the polymer injection has been known as the effective treatment to increase the profits. For better performance and maximum profit, the operating conditions of polymer flooding regarding the location of injection well and the concentration of polymer solution need to be thoroughly investigated. In this work, numerical simulations were used to examine the effects of the conditions on performance of polymer flooding under bottom-water aquifer oil reservoir.
This work describes a fully integrated evaluation ofpolymer Enhanced Oil Recovery project applied on the reservoir with strong bottom-water aquifer. The comparison was made regarding the oil recovery, water cut, and economic feasibility of polymer flood to find the optimal design of well location and polymer concentration. The NPV has been used to evaluate economics of the work. Not only the operating conditions, but also geological properties of the reservoir have uncertainties. Considering uncertainties, the effects of undetected geological event on the NPV of polymer flooding is analysed by sensitivity analysis.
-
-
-
Improved Recovery by Optimizing Water Flooding - An Experimental Approach
Authors A. Chaturvedi and G. SinghSummarySince the inception of water flooding it has been used to improve recovery from oil reservoirs mainly light and medium oil and has very high success rate than other methods due to high recovery factor and low costs associated with it. Clay minerals are present as rock matrix in sandstone reservoir and adversely affect during water flooding as they swell and decrease the porosity and block the pore throat thus resulting in reduced production. An experimental study was done to determine formation damage due to clay swelling, and to identify a cost effective clay stabilizer to be used in the injection water. The study included performing core flood experiments using sandstone reservoir cores, analysing the effects of stabilizer type and concentration on permeability of core in detail and selecting critical salt concentration, below which there is loss of permeability occurs. Based on the data obtained, analysis of change in porosity and permeability was done. With the help of data obtained, clay swelling effect has been seen while flooding with distilled water; it reduces by the use of clay stabilizer. At the same time use of brine in place of distilled water increases recovery efficiency of water flooding, thus improving recovery.
-
-
-
Extracting Quality Factor by Spectral Simulation Method
More LessSummaryQuality factor Q reflects the strength of seismic wave attenuation, and it is an important parameter on hydrocarbon detection and reservoir description. The article selects the appropriate function to fit the seismic spectrum. Combined with the energy attenuation law, we find that the spectral fitting coefficient can be divided into three categories: related to the absorption and attenuation; associated with the energy attenuation of non-frequency (e.g., diffusion, reflection, transmission, etc.); and unrelated to the energy attenuation. According to the fitting coefficients related to the absorption and attenuation, we can calculate the quality factor Q from inversion. Model test without noise shows that extracting Q value from fitting coefficients can reflect the Q values trend of formation. Under the condition of weak noise, based on the different variation rules of three kinds of fitting coefficients, firstly, we calculate the expectation of fitting coefficients that is unrelated to the attenuation. Secondly, take a two-order fitting for the rest of the coefficients to improve the inversion precision of the formation parameters. The results of model tests confirm the theoretical feasibility of this method. It gets good application effect after inverse Q filter.
-