ANALYSIS OF

RESERVOIR CHARACTERIZATION

BYMOHAMMED ABDUL GHAFOOR

4th YEARDEPARTMENT OF PETROLEUM ENGINEERING

CONTENT• INTRODUCTION

• STUDY UNDER VARIOUS DISCIPLINE

• OBJECTIVES OF ANALYSING RESERVOIR CHARACTERISTICS

• PROCEDURE OF HOW TO ANALYSE

• ADVANCES IN RESERVOIR CHARACTERIZATION

• SUMMARY

• CONCLUSION

• REFERENCES

INTRODUCTION• Reservoir characterization attempts to create a static and

dynamic three dimensional description of an oil and gas reservoir

• Reservoir characterization is a combined technology associated with geo statistics, geo physics, petro physics, geology and reservoir engineering

• The main goals is to aid field development and reservoir management teams, in describing the reservoir in sufficient detail

AIMS OF MODELLING• STATIC MODELLING

1. Define quantity and distribution of porosity, saturation and permeability in each well

2. Interpolate rock property data between wells & extrapolate cored data to un cored wells

3. Identify flow units from porosity v/s permeability population

• DYNAMIC MODELLING

1. Test the static model for accuracy by matching product history

2. Predict future performance under various operational scenario

3. Optimize production for maximum long term economic return

OBJECTIVES

The evaluation of well logs to obtain reservoir rock & fluid properties, such as shale volume, porosity, water saturation, permeability, and lithology etc

Developing 3D/4D data for reservoir development planning to obtain higher recoveries with fewer wells in better positions at minimum cost through optimization, increasing reserves

Making decisions regarding the development of the field

The dynamic reservoir model as a template for design and economic evaluation of production, gathering, treating, and pipeline equipment required to handle the predicted reservoir performance.

The timing of compressor installations, water disposal wells, and conversion of wells to injection are paramount considerations.

STUDY OF THE RESERVOIR CHARACTERIZATION UNDER VARIOUS DISCIPLINES• Petro physicists : Evaluation of

well logs to obtain reservoir rock and fluid properties, such as shale volume, porosity, water saturation, permeability, and lithology on a foot by foot basis, as well as sums and averages over specific reservoir units.

• Geologists: the interpretation and mapping of petro graphic results, core analysis, petro physical rock properties, and seismic attributes into stratigraphic sequences and/or flow units

• Reservoir engineers : The analysis & interpretation of pressure transient data from drill stem tests or production tests. Flow capacity and distance to reservoir boundaries are the usual results obtained.

interpretation

PRACTICAL PROCEDUREIn this section, practical workflow to carry out reservoir characterization research has been conducted. This Procedure is comprised of these steps.

I. Depositional background and sedimentary environmental analysis

II. Stratigraphic framework and structural modelling

III. Establishment of reservoir sedimentary model

IV. Reservoir prediction with applications of high resolution seismic

V. Establishment of comprehensive reservoir architecture model

VI. Establishment of comprehensive and integrated reservoir geological model

Depositional background and sedimentary environmental analysis

• Study of the regional depositional background and sedimentary environment can provide basic and qualitative knowledge to reservoir architecture and is the foremost step for the reservoir characterization

Stratigraphic framework and structural modelling

• Stratigraphic division, correlation and structural interpretation are the basis for study of reservoir architecture. Appropriate stratigraphic framework can accurately characterize reservoir architecture and improve the precision and reliability of reservoir prediction.

Establishment of reservoir sedimentary model

• Genetic units, sand spatial distribution and superimposed pattern can be identified through Micro facies subdivision. Micro facies analysis is the key technique in this step and study on sedimentary facies is essential throughout stages of oilfield exploration and development.

Reservoir prediction with applications of high resolution seismic

• Based on the previous four steps which focus on sedimentary studies and in combination of seismic data, inter-well reservoir distribution prediction should be more reliable.

Establishment of comprehensive reservoir architecture model

• At early stage of field development or at exploration stage, the priority for reservoir characterization should be investigation for reservoir architecture and characterization of reservoir heterogeneity

• At mature stage of field development, the key target for reservoir characterization should be focused on the reservoir compartments which are separated or laminated

Establishment of integrated reservoir geological model• As subsurface reservoir model is a computer based representation

of petro physical parameters such as porosity, permeability, fluid saturation etc.

• Through previous steps, various parameters needed have been well prepared.

• In this step, 3D subsurface reservoir model can be finally established with calibration of existing data

• Now, the key factor is the optimization of modelling method and integration of geologist’s expert knowledge

ADVANCES IN RESERVOIR CHARACTERIZATION• Material improvements and technical innovations have lead to the advances

of reservoir characterization technology.

1. Advanced instruments and technologies applied in data gathering, processing and monitoring have improved quality and reliability of test data

2. The second is that the development of related technology such as computer science and information science has realized comprehensive integration of reservoir characterization with outcrop analogues, seismic, geology and well logs

SUMMARY• Reservoir characterization has attracted a remarkable research efforts particularly

in the past three decades. Reservoir characterization is a combined technology associated with geo statistics, geophysics, petro physics, geology and reservoir engineering and the main goals of reservoir characterization research are to aid field development and reservoir management teams in describing the reservoir in sufficient details, developing 3D/4D data for reservoir development planning to obtain higher recoveries with fewer wells in better position at minimum cost through optimization, increasing reserves, improving simulation and completion practices and reducing to a minimum uncertainty in production forecast. Reservoir Description means many things to many people. It is a multi-disciplinary approach with which can generate the most complete reservoir characterization.

CONCLUSION• In this paper, discussions were carried on description & modelling of

the reservoir based on Logging, Seismic survey & Geological study• It is for the purpose of improving estimation of reserves and making

decisions regarding the development of the field & to optimize production• Resolution improvement for seismic survey, effective methods to

appropriately characterize cross well petro physical properties and hydrocarbon distribution and effective way to characterize dynamic changes of petro physical properties should be three main development trends for reservoir characterization technology.

REFERENCES• http://cdn.intechopen.com/pdfs-wm/27593.pdf

• https://www.spec2000.net/01-resdesc.htm

• http://Basic_elements_of_a_reservoir_characterization_study

QUESTIONS?