Coupling Sequential-Self calibration and Genetic Algorithms to Integrate Production Data in Geostatistical Reservoir Modeling

Author(s):  
Xian-Huan Wen ◽  
Tina Yu ◽  
Seong Lee
1996 ◽  
Author(s):  
Richard R. Brooks ◽  
S. Sitharama Iyengar ◽  
Jianhua Chen

3D Research ◽  
2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Nabil El Akkad ◽  
Soulaiman El Hazzat ◽  
Abderrahim Saaidi ◽  
Khalid Satori

Author(s):  
Maxime Conjard ◽  
Dario Grana

AbstractData assimilation in reservoir modeling often involves model variables that are multimodal, such as porosity and permeability. Well established data assimilation methods such as ensemble Kalman filter and ensemble smoother approaches, are based on Gaussian assumptions that are not applicable to multimodal random variables. The selection ensemble smoother is introduced as an alternative to traditional ensemble methods. In the proposed method, the prior distribution of the model variables, for example the porosity field, is a selection-Gaussian distribution, which allows modeling of the multimodal behavior of the posterior ensemble. The proposed approach is applied for validation on a two-dimensional synthetic channelized reservoir. In the application, an unknown reservoir model of porosity and permeability is estimated from the measured data. Seismic and production data are assumed to be repeatedly measured in time and the reservoir model is updated every time new data are assimilated. The example shows that the selection ensemble Kalman model improves the characterisation of the bimodality of the model parameters compared to the results of the ensemble smoother.


2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
Tina Yu ◽  
Dave Wilkinson ◽  
Alexandre Castellini

Reservoir modeling is a critical step in the planning and development of oil fields. Before a reservoir model can be accepted for forecasting future production, the model has to be updated with historical production data. This process is called history matching. History matching requires computer flow simulation, which is very time-consuming. As a result, only a small number of simulation runs are conducted and the history-matching results are normally unsatisfactory. This is particularly evident when the reservoir has a long production history and the quality of production data is poor. The inadequacy of the history-matching results frequently leads to high uncertainty of production forecasting. To enhance the quality of the history-matching results and improve the confidence of production forecasts, we introduce a methodology using genetic programming (GP) to construct proxies for reservoir simulators. Acting as surrogates for the computer simulators, the “cheap” GP proxies can evaluate a large number (millions) of reservoir models within a very short time frame. With such a large sampling size, the reservoir history-matching results are more informative and the production forecasts are more reliable than those based on a small number of simulation models. We have developed a workflow which incorporates the two GP proxies into the history matching and production forecast process. Additionally, we conducted a case study to demonstrate the effectiveness of this approach. The study has revealed useful reservoir information and delivered more reliable production forecasts. All of these were accomplished without introducing new computer simulation runs.


2015 ◽  
Vol 54 (5) ◽  
pp. 053115 ◽  
Author(s):  
Francisco Carlos Mejía Alanís ◽  
J. Apolinar Muñoz Rodríguez

2010 ◽  
Author(s):  
◽  
Amirmasoud Kalantari-Dahaghi ◽  

The intent of this study is to reassess the potential of New Albany Shale formation using a novel and integrated workflow, which incorporates field production data and well logs using a series of traditional reservoir engineering analyses complemented by artificial intelligence & data mining techniques. The model developed using this technology is a full filed model and its objective is to predict future reservoir/well performance in order to recommend field development strategies.;The impact of different reservoir characteristics such as matrix porosity, matrix permeability, initial reservoir pressure and pay thickness as well as the length and the orientation of horizontal wells on gas production in New Albany Shale have been presented.;The study was conducted using publicly available numerical model, specifically developed to simulate gas production from naturally fractured reservoirs.;The study focuses on several New Albany Shale (NAS) wells in Western Kentucky. Production from these wells is analyzed and history matched. During the history matching process, natural fracture length, density and orientations as well as fracture bedding of the New Albany Shale are modeled.;Sensitivity analysis is performed to identify the impact of reservoir characteristics and natural fracture aperture, density and length on gas production, using information found in the literature and outcrops and by performing sensitivity analysis on key reservoir and fracture parameters.;Then, the history-matched results of 87 NAS wells have been used to develop a full field reservoir model using an integrated workflow, named Top-Down, Intelligent Reservoir Modeling. In this integrated workflow unlike traditional reservoir simulation and modeling, we do not start from building a geo-cellular model. Top-Down intelligent reservoir modeling starts by analyzing the production data using traditional reservoir engineering techniques such as Decline Curve Analysis, Type Curve Matching, Single-well History Matching, Volumetric Reserve Estimation and Recovery Factor. These analyses are performed on individual wells in a multi-well New Albany Shale gas reservoir in Western Kentucky that has a reasonable production history. Data driven techniques are used to develop single-well predictive models from the production history and the well logs (and any other available geologic and petrophysical data).;Upon completion of the abovementioned analyses a large database is generated. This database includes a large number of spatio-temporal snap shots of reservoir behavior. Artificial intelligence and data mining techniques are used to fuse all these information into a cohesive reservoir model. The reservoir model is calibrated (history matched) using the production history of the most recent set of wells that have been drilled in the field. The calibrated reservoir model is utilized for predictive purposes to identify the most effective field development strategies including locations of infill wells, remaining reserves, and under-performer wells. Capabilities of this new technique, ease of use and much shorter development and analysis time are advantages of Top-Down modeling as compared to the traditional simulation and modeling.;In addition, 31 recently drilled well in Christian county Western Kentucky-Halley's Mills quadrangle have been used to perform Top-down modeling. Zone manager feature of Geographix software is used. The available production data are going to be the attributes in this feature. The contours are generated and the results have been compared with the result of Top-down modeling (Fuzzy pattern recognition). Structural map, isopach map and the other geological map has been generated using Geographix.;Additionally, in order to indentify the effect of horizontal lateral length on well productivity from New Albany Shale, fracture network has been regenerated in order to represent the distribution of natural fracture in that formation.


Author(s):  
О. V. Burachok ◽  
D. V. Pershyn ◽  
S. V. Matkivskyi ◽  
Ye. S. Bikman, Ye. S. Bikman ◽  
О. R. Kondrat

The article characterizes the key difficulties which emerge during the simulation of phase behaviors described using the model of “black oil” or fully functional compositional model with the help of the equation-of-state (EOS) in order to create valid continuously operating geological-technological 3D models of gas-condensate reservoirs. The input data for 3D filtration reservoir modeling, the development of which started in the 1960s, are the results of initial gas-condensate and thermodynamic studies. Hydrocarbon component composition of reservoir gas in the existing gas-condensate studies is given only to fraction C5+. Taking into account the peculiarities of initial thermodynamic research with the use of the differential condensation experiment and the absence of such type of experiment in the list of standard experiments in commercially-available PVT-simulators, there appeared a need to develop rational approaches and techniques for correct integration of existing geological-production data in PVT modeling. This article describes the methods for adjusting Peng-Robinson equation-of-state under the condition of input data shortage. Depending on initial data availability and quality, the authors have suggested two different methods. The first PVT-modeling method, which makes it possible to adjust the equation-of-state, is based on the data of component composition of gases and fractional composition of the stable condensate. In case the data of fractional composition of the stable condensate are not available, the authors suggest the second method that is the splitting of fraction C5+ following Whitson volumetric methodology. The suggested methods and two different approaches to EOS adjustment allow effective PVT-modeling using available geological and production data. Study results are presented as the graphical dependencies of comparison of potential hydrocarbons C5+content change in reservoir gas before and after configuring the equation-of-state, as well as the synthetic “liquid saturation” loss curve of the CVD experiment.


2005 ◽  
Vol 173 (4S) ◽  
pp. 121-121
Author(s):  
Hari Siva Gurunadha Rao Tunuguntla ◽  
P.V.L.N. Murthy ◽  
K. Sasidharan

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