AMBIGUITY AND INTERPRETATION
This project is about reservoir characterization study, which based on a reservoir modeling technique and predicts the liquid demeanor in the reservoir. The model is produced applying data from all geographic expedition and growth origins through particularly the output data and liquified chemical science. This information is acquired through observation of 3D seismic study. While all information is diagrammed in 3D model of reservoir substances is produced which is then utilized to assist pick the most suitable and efficient organic compound convalescence technique.
Reservoir Characterization is very necessary to advance understanding to optimize and gauge reservoir’s performance and its qualities. The better understanding reservoir, the better positioned are to make it as perfect, functional or effective as possible in its lifetime performance. Understanding reservoir rocks and fluids through accurate measurements, surveys and characterization delivered by efficient tools, services, and petro technical expertise help stimulate concerntratoin process.
Introduction
This paper uses basic kriging to obtain top and bottom formation surfaces from the 10 wells, it provides QC on each well and all, variagoram, calculates bulk rock volume from the above (OWC plane given) and calculates net-gross ratios. The reservoir model is an arrangement of quantitative agreement of geological and physical properties. The reservoir model must be distinguished from the calculation, which includes only a geometrical shape of the reservoir.
For example, a model of the formation may be layered formation. The computational scheme is the formation during the same model and it can be represented as a layer of circular shape and the straight seam. Reservoir models and extraction activities of their gas clothed in mathematical form are characterized by certain mathematical relationships. The main objective of the development of gas fields is to make the calculation model based on individual insights gained because of geological, geophysical, and hydrodynamic studies of the deposit. According to the geological, geophysical and hydrodynamic studies, to get a very contrasting picture of the deposit. In the calculation model should be rated by highlighting the main personality of simulated layers and describing them quantitatively.
Traditionally, all the abundance of hydrocarbon reservoirs reduces the formation of certain types of models, which will be further discussed. One of the main features of the gas-bearing rock is a difference of reservoir parameters of porosity, gas saturation and permeability) formations in some areas. This spatial variability of the parameters of reservoir rocks of hydrocarbons called lithologic heterogeneity of the reservoir. Second main feature of the collectors - the presence of cracks in them, ie, fractured reservoirs. In the development of these deposits, individuality breeds have a more significant influence on the extraction of hydrocarbons from them. Reservoir models with a certain degree of conditionality are divided into deterministic, probabilistic, and statistical.
Analysis
Reservoir models are useful in determining reservoir uncertainty, the estimation of fluids volume and may be used in some form to stimulate the flow of fluids through the reservoir. A huge challenge in reservoir characterization is accounting for pore structure, metastability, mineralogy and geological heterogeneity, for example: Multiple pore systems and rock textures of reservoir material at the microscopic scales while faithfully representing these properties in larger scale simulation models. The primary challenge is accurate integration of data from different scales. The primary challenge is accurate integration of data from different scales.
Up-scaling
Up-scaling has turnout to be a progressively significant instrument in modern era for converting extremely elaborated geological models to simulation grids. Up-scaling applying flow units of measurement for reservoir depiction, it would be idealistic to integrate geological and petro-physical data point at the scale at which the information is useable. A fine-scale reservoir explanation and a simulation grid, an Up-scaling algorithm puts suited measures for porosity, permeability and other flow operation to cells on the harsh simulation grid.
Quality control Analysis
A key step in any study is EDA. In this step, quality control of the data is critical because the relationships between key variables and general data characteristics are identified using various tools, including both classical and geostatistical methods.Data quality control and quality assurance (QC/QA) are essential for execution of successful geologic modeling and reservoir characterization programs. The data gained or gathered at all levels of geographic expedition, assessment, growth and fluid product should be subjected to stringent QC/QA procedures. These data should be organized and stored in a data management system that is accessible to a multidisciplinary team. The QA/QC program applied to each data set varies with the type of data. It is important to emphasize that a comprehensive QA/QC program should be devised for each data type and the program should be under the management of a professional with experience in the acquisition, collection, and processing of that particular type of data.
Modelling the Scale
Major issue is the great importance of data intensities to be addressed. The most advantageous workflow uses an appropriate fine-scale model as a guide when defining the flow units and constructing the flow-simulation grid. Both approaches undoubtedly will decrease or “smooth” the existing heterogeneity, but modeling first at a finer scale can produce a more informative, upscaled grid that preserves the critical heterogeneity.
Fig.1: geo3D’ Model
Problem
This paper carried out a pilot study in a field in exploration stage. In relation to it, 3D seismic revealed that the basin has been subject to significant subsidence and faulting. A number of exploration wells have been drilled over a 10km by 10km section of the projected reservoir and several wells intersected an oil-water contact. On basin scale, the 3kmdeep reservoir dips gently to the east. The reservoir is strongly compartmentalized, and all faults are assumed sealing. This paper is analyzes a 2km by 2km compartment of the reservoir, surrounded by vertical sealing faults on all sides and covered by thick sealing shale. Pilot study and survey is conducted on oil and gas fields to check and weigh different aspects of rocks and fluids beneath the surface. It is quite an essential step to check the feasibility of the oil and gas exploration fields.
- Pilot Study in brief
- A pilot study is designed to obtain preliminary data important for the planning of further phases of the study (definition capabilities of the study in a larger number of subjects, the sample size in future research, the study of necessary capacity. A pilot study is designed to obtain preliminary data important for the planning of further phases of the study definition capabilities of the study in a larger number of subjects, the sample size in future research, and the necessary power measurements. It is a mini-simulation of a large survey or questionnaire in order to obtain reliable results. The cost of such a study is generally up to 5% of the total budget of research. It allows identifying the shortcomings of field research.
- Seismic Survey
The concept of "seismic" includes geophysical methods for studying the Earth's crust, based on a study of artificially excited elastic waves. With the seismic study the deep structure of the Earth, stand out mineral deposits (mainly oil and gas); solve problems of hydrogeology and engineering geology. Seismic exploration is robust, high-resolution, adaptability and a huge amount of information obtained.
The basis of seismic methods is based on the excitation of elastic waves by a special technical complex source. As a result, of the geological environment responds to the emergence of a periodic oscillation process and the formation of an elastic wave. Spreading for rock, elastic wave strikes the boundary, and changes the direction of the dynamic properties, the formation of new wave. The path of the waves placed the observation point, where with the help of special instruments seismometers are determined by the properties of oscillatory processes. From them data, extract useful information about the structure and composition of the medium under study. The most effective seismic survey in the study of the sedimentary cover of the ancient platforms, since it horizontally layered structure is most easily interpreted seismic data. With the increase in the slope of target geological boundaries reliability of the seismic data drops sharply.
The claim that one is able to see through the thick rock treasures hidden deep underground, can still seem much fantastic. No fiction: such work is carried out successfully all over the world to search for hydrocarbons. And this technology is used for seismic surveys - a tool that allows oil companies to see the geological structure up to several kilometers deep into the Earth. Images obtained with the use of this technology, are more informative if they get used to the three-dimensional seismic survey (or, as it is called, seismic 3D). In the oil companies, the technology is effectively applied not only to new development, but also to maintain production levels in mature fields.
Figure 1: Seismic waves for survey
- Horizons
Horizons are earth's surface that divides diverse rock layers in dethronement surroundingses characterized by dissimilar contemplation dimensions.
Above schematic diagram describes full oil & gas exploration methodology.
- Purpose of Report
In this report, a field exploration scenario is described. The purpose of the report is to conduct the reservoir characterization study of the described reservoir. Conducting pilot study in field exploration is of utmost importance. The focus of study is on dealing with reservoir heterogeneity and exploring some of the techniques commonly needed in spatial estimation and up scaling.
- Problem Statement
- Calculate Bulk Rock Volume (BRV) of reservoir based on provided oil-water contact.
- Carry out quality control on well data.
- Using fine scale model, calculate relevant measures like BRV, net to gross.
Given MATLAB Code gave the following results in the form of figures showing grid.
Conclusion
Three-dimensional numerical earth models are playing an increasingly important role in prospecting and exploration for better control of field development and optimization of hydrocarbon recovery. The main objective of Petroleum Geophysicists is quantitative aggregation of three-dimensional and four-dimensional seismic data in static and dynamic graphs modeling of mineral resources. Combining theory and illustrations based on a wide range of practical examples, this study has presented the best current experience and future challenges in the field of restriction patterns subsurface using seismic data. Particular emphasis is on the integration of seismic data in terms of worker threads "from seismic to simulation." This paper conducted a pilot study at exploration stage in a field of 10 wells. This study has to analyze the compartments of the reservoir on the basin scale given in the problem, which has explained in detail in the next section of introduction. The focus of this study was on dealing with reservoir heterogeneity and exploring some of the techniques commonly needed in Up-scaling and spatial estimation.Often, the goal of a project was to provide a general description and analysis of a data set, and this can be done utilizing classical statistical instruments in a procedure usually experienced as explorative data analysis (EDA).
Bibliography
Huang, Xuri, Western Geophysical) Laurent Meister (SPE, and Western Geophysical) Rick Workman (SPE. 1997. “Reservoir Characterization by Integration of Time-Lapse Seismic and Production Data.” In SPE Annual and Technical Conference.
Pivot, F., and D. Modin. 2010. “A Step beyond Empirical Approaches of Seismic Reservoir Characterization.” EAGE (June 2010): 14 – 17.
Waggoner, John, Stephen Pickering, J. Eric Bickel, Richard Gibson, and Duane McVay. 2008. “Quantifying the Reliability and Value of 3D Land Seismic.” SPE Reservoir Evaluation & Engineering. doi:10.2118/102340-PA.
