Integrating core and log data in the petrophysical rock type approach to identify flow units and predict permeability in a carbonate reservoir of Campos Basin

2017 ◽  
Author(s):  
Heitor Lichotti ◽  
Abel Carrasquilla
Keyword(s):  
Rock Type ◽  
Carbonate Reservoir ◽  
Log Data ◽  
Flow Units ◽  
Campos Basin

Improved Prediction of Reservoir Behavior Through Integration of Quantitative Geological and Petrophysical Data

1999 ◽  
Vol 2 (02) ◽  
pp. 149-160 ◽  
Author(s):  
D.K. Davies ◽  
R.K. Vessell ◽  
J.B. Auman
Keyword(s):  
Body Size ◽  
Reservoir Characterization ◽  
Rock Type ◽  
Carbonate Reservoir ◽  
High Porosity ◽  
Geometrical Characteristics ◽  
Rock Types ◽  
Flow Units ◽  
Reservoir Description ◽  
Pore Body

Summary This paper presents a cost effective, quantitative methodology for reservoir characterization that results in improved prediction of permeability, production and injection behavior during primary and enhanced recovery operations. The method is based fundamentally on the identification of rock types (intervals of rock with unique pore geometry). This approach uses image analysis of core material to quantitatively identify various pore geometries. When combined with more traditional petrophysical measurements, such as porosity, permeability and capillary pressure, intervals of rock with various pore geometries (rock types) can be recognized from conventional wireline logs in noncored wells or intervals. This allows for calculation of rock type and improved estimation of permeability and saturation. Based on geological input, the reservoirs can then be divided into flow units (hydrodynamically continuous layers) and grid blocks for simulation. Results are presented of detailed studies in two, distinctly different, complex reservoirs: a low porosity carbonate reservoir and a high porosity sandstone reservoir. When combined with production data, the improved characterization and predictability of performance obtained using this unique technique have provided a means of targeting the highest quality development drilling locations, improving pattern design, rapidly recognizing conformance and formation damage problems, identifying bypassed pay intervals, and improving assessments of present and future value. Introduction This paper presents a technique for improved prediction of permeability and flow unit distribution that can be used in reservoirs of widely differing lithologies and differing porosity characteristics. The technique focuses on the use and integration of pore geometrical data and wireline log data to predict permeability and define hydraulic flow units in complex reservoirs. The two studies presented here include a low porosity, complex carbonate reservoir and a high porosity, heterogeneous sandstone reservoir. These reservoir classes represent end-members in the spectrum of hydrocarbon reservoirs. Additionally, these reservoirs are often difficult to characterize (due to their geological complexity) and frequently contain significant volumes of remaining reserves.1 The two reservoir studies are funded by the U.S. Department of Energy as part of the Class II and Class III Oil Programs for shallow shelf carbonate (SSC) reservoirs and slope/basin clastic (SBC) reservoirs. The technique described in this paper has also been used to characterize a wide range of other carbonate and sandstone reservoirs including tight gas sands (Wilcox, Vicksburg, and Cotton Valley Formations, Texas), moderate porosity sandstones (Middle Magdalena Valley, Colombia and San Jorge Basin, Argentina), and high porosity reservoirs (Offshore Gulf Coast and Middle East). The techniques used for reservoir description in this paper meet three basic requirements that are important in mature, heterogeneous fields.The reservoir descriptions are log-based. Flow units are identified using wireline logs because few wells have cores. Integration of data from analysis of cores is an essential component of the log models.Accurate values of permeability are derived from logs. In complex reservoirs, values of porosity and saturation derived from routine log analysis often do not accurately identify productivity. It is therefore necessary to develop a log model that will allow the prediction of another producibility parameter. In these studies we have derived foot-by-foot values of permeability for cored and non-cored intervals in all wells with suitable wireline logs.Use only the existing databases. No new wells will be drilled to aid reservoir description. Methodology Techniques of reservoir description used in these studies are based on the identification of rock types (intervals of rock with unique petrophysical properties). Rock types are identified on the basis of measured pore geometrical characteristics, principally pore body size (average diameter), pore body shape, aspect ratio (size of pore body: size of pore throat) and coordination number (number of throats per pore). This involves the detailed analysis of small rock samples taken from existing cores (conventional cores and sidewall cores). The rock type information is used to develop the vertical layering profile in cored intervals. Integration of rock type data with wireline log data allows field-wide extrapolation of the reservoir model from cored to non-cored wells. Emphasis is placed on measurement of pore geometrical characteristics using a scanning electron microscope specially equipped for automated image analysis procedures.2–4 A knowledge of pore geometrical characteristics is of fundamental importance to reservoir characterization because the displacement of hydrocarbons is controlled at the pore level; the petrophysical properties of rocks are controlled by the pore geometry.5–8 The specific procedure includes the following steps.Routine measurement of porosity and permeability.Detailed macroscopic core description to identify vertical changes in texture and lithology for all cores.Detailed thin section and scanning electron microscope analyses (secondary electron imaging mode) of 100 to 150 small rock samples taken from the same locations as the plugs used in routine core analysis. In the SBC reservoir, x-ray diffraction analysis is also used. The combination of thin section and x-ray analyses provides direct measurement of the shale volume, clay volume, grain size, sorting and mineral composition for the core samples analyzed.Rock types are identified for each rock sample using measured data on pore body size, pore throat size and pore interconnectivity (coordination number and pore arrangement).

scholarly journals PETROPHYSICAL CHARACTERIZATION OF ALBIAN CARBONATE RESERVOIR IN CAMPOS BASIN USING A MULTIVARIATE APPROACH WITH WELL LOGS AND LABORATORY MEASUREMENTS

2018 ◽  
Vol 36 (2) ◽  
pp. 123
Author(s):  
Antonio Abel Carrasquilla ◽  
Raphael Ribeiro Silva
Keyword(s):  
Cluster Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Water Saturation ◽  
Laboratory Data ◽  
Carbonate Reservoir ◽  
Well Logs ◽  
Flow Units ◽  
Rock Typing ◽  
Campos Basin

ABSTRACT. This study characterizes an Albian carbonate reservoir of Field B in the Campos Basin, based on geophysical well logs and laboratory petrophysical data. This permitted us to estimate the porosity, permeability and water saturation of this reservoir more reliably. In order to achieve this goal, the Cluster Analysis for Rock Typing module of the Interactive Petrophysics software was used to divide the well into electrofacies. For each of them, an equation was determined to find the porosity and the permeability, using the multiple linear regression technique, using as input the log data and as target the laboratory data. The obtained results were compared with different models proposed by other authors, with the best results being found with multiple linear regression. Water saturation, on the other hand, was estimated by Archie equation after identifying the cementation coefficient with the Pickett crossplot. Finally, the porosity and permeability data were again used to now identify three main flow units in the reservoir through the Winland graph. To verify the effectiveness of the adopted methodology, it was successfully applied in a blind test, defining poros-ity, permeability, water saturation and flow units in a well without laboratory data. Keywords: well logging, Field B, petrophysics, carbonate reservoir, Albian.RESUMO. Este estudo caracteriza um reservatório carbonático Albiano do Campo B na Bacia de Campos, a partir de dados de perfis de poço e de petrofísica de laboratório. Uma estimativa da porosidade, da permeabilidade e da saturação de água de forma mais confiável. Com ese objetivo, foi usado o módulo Cluster Analysis for Rock Typing do software Interactive Petrophysics para dividir o poço em eletrofácies. Para cada uma delas, foi determinada uma equação para a porosidade e a perme-abilidade, através da técnica de regressão linear múltipla, usando como entrada os dados de perfis de poço e como alvo os dados de laboratório. Esses resultados foram comparados com modelos propostos por outros autores, sendo os melhores aqueles obtidos com regressão linear múltipla. A saturação de água foi estimada com a Equação de Archie após identificar o coeficiente de cimenta-ção com o crossplot de Pickett. Finalmente, os dados de porosidade e permeabilidade foram usados para identificar três unidades de fluxo através do gráfico de Winland. Para verificar a eficácia da metodologia adotada, a mesma foi aplicada com sucesso num teste cego, definindo a porosidade, a permeabilidade, a saturação de água e as unidades de fluxo num poço sem dados de laboratório. Palavras-chave: perfis de poços, Campo B, petrofísica, reservatório carbonático, Albiano.   

ANALISA POTENSI MINYAK DAN GAS BUMI DENGAN ATRIBUT SEISMIK PADA BATUAN KARBONAT LAPANGAN *ZEFARA* CEKUNGAN SUMATRA SELATAN

KURVATEK ◽  
2017 ◽  
Vol 1 (2) ◽  
pp. 21-31
Author(s):  
Fatimah Miharno
Keyword(s):  
Instantaneous Frequency ◽  
Carbonate Reservoir ◽  
Control Analysis ◽  
High Porosity ◽  
Hydrocarbon Accumulation ◽  
Seismic Attribute ◽  
Data Set ◽  
Log Data ◽  
Low Amplitude ◽  
Rms Amplitude

ABSTRACT*Zefara* Field formation Baturaja on South Sumatra Basin is a reservoir carbonate and prospective gas. Data used in this research were 3D seismik data, well logs, and geological information. According to geological report known that hidrocarbon traps in research area were limestone lithological layer as stratigraphical trap and faulted anticline as structural trap. The study restricted in effort to make a hydrocarbon accumulation and a potential carbonate reservoir area maps with seismic attribute. All of the data used in this study are 3D seismic data set, well-log data and check-shot data. The result of the analysis are compared to the result derived from log data calculation as a control analysis. Hydrocarbon prospect area generated from seismic attribute and are divided into three compartments. The seismic attribute analysis using RMS amplitude method and instantaneous frequency is very effective to determine hydrocarbon accumulation in *Zefara* field, because low amplitude from Baturaja reservoir. Low amplitude hints low AI, determined high porosity and high hydrocarbon contact (HC).  Keyword: Baturaja Formation, RMS amplitude seismic attribute, instantaneous frequency seismic attribute

Enhanced and Rock Typing-Based Reservoir Characterization of the Palaeocene Harash Carbonate Reservoir-Zelten Field-Sirte Basin-Libya

2021 ◽  
Author(s):  
Mohamed Masoud ◽  
W. Scott Meddaugh ◽  
Masoud Eljaroshi ◽  
Khaled Elghanduri
Keyword(s):  
Rock Type ◽  
Carbonate Reservoir ◽  
Classification Model ◽  
Reservoir Rocks ◽  
The Core ◽  
Core Samples ◽  
Rock Types ◽  
Rock Typing ◽  
Open Hole ◽  
Type Classification

Abstract The Harash Formation was previously known as the Ruaga A and is considered to be one of the most productive reservoirs in the Zelten field in terms of reservoir quality, areal extent, and hydrocarbon quantity. To date, nearly 70 wells were drilled targeting the Harash reservoir. A few wells initially naturally produced but most had to be stimulated which reflected the field drilling and development plan. The Harash reservoir rock typing identification was essential in understanding the reservoir geology implementation of reservoir development drilling program, the construction of representative reservoir models, hydrocarbons volumetric calculations, and historical pressure-production matching in the flow modelling processes. The objectives of this study are to predict the permeability at un-cored wells and unsampled locations, to classify the reservoir rocks into main rock typing, and to build robust reservoir properties models in which static petrophysical properties and fluid properties are assigned for identified rock type and assessed the existed vertical and lateral heterogeneity within the Palaeocene Harash carbonate reservoir. Initially, an objective-based workflow was developed by generating a training dataset from open hole logs and core samples which were conventionally and specially analyzed of six wells. The developed dataset was used to predict permeability at cored wells through a K-mod model that applies Neural Network Analysis (NNA) and Declustring (DC) algorithms to generate representative permeability and electro-facies. Equal statistical weights were given to log responses without analytical supervision taking into account the significant log response variations. The core data was grouped on petrophysical basis to compute pore throat size aiming at deriving and enlarging the interpretation process from the core to log domain using Indexation and Probabilities of Self-Organized Maps (IPSOM) classification model to develop a reliable representation of rock type classification at the well scale. Permeability and rock typing derived from the open-hole logs and core samples analysis are the main K-mod and IPSOM classification model outputs. The results were propagated to more than 70 un-cored wells. Rock typing techniques were also conducted to classify the Harash reservoir rocks in a consistent manner. Depositional rock typing using a stratigraphic modified Lorenz plot and electro-facies suggest three different rock types that are probably linked to three flow zones. The defined rock types are dominated by specifc reservoir parameters. Electro-facies enables subdivision of the formation into petrophysical groups in which properties were assigned to and were characterized by dynamic behavior and the rock-fluid interaction. Capillary pressure and relative permeability data proved the complexity in rock capillarity. Subsequently, Swc is really rock typing dependent. The use of a consistent representative petrophysical rock type classification led to a significant improvement of geological and flow models.

Flow Units Characterization in a Dual Porosity-Permeability Carbonate Reservoir: A Case Study from Western Offshore, India

2010 ◽  
Author(s):  
Ajay Kumar ◽  
Aks Kakani ◽  
Calvert Stefan ◽  
Sutapa Bhadra ◽  
Arpana Sarkar ◽  
...  
Keyword(s):  
Carbonate Reservoir ◽  
Dual Porosity ◽  
Flow Units

scholarly journals Corrigendum to “Numerical Simulation Modeling of Carbonate Reservoir Based on Rock Type”

2018 ◽  
Vol 2018 ◽  
pp. 1-1
Author(s):  
Peiqing Lian ◽  
Cuiyu Ma ◽  
Bingyu Ji ◽  
Taizhong Duan ◽  
Xuequn Tan
Keyword(s):  
Numerical Simulation ◽  
Simulation Modeling ◽  
Rock Type ◽  
Carbonate Reservoir
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