This document provides an overview and summary of the key topics covered during an internship on reservoir engineering and software applications at the Directorate General of Hydrocarbons. It discusses fundamentals of reservoir engineering including properties like porosity, permeability, saturation and wettability. It also summarizes the use of reservoir simulation software like OilField Manager and Petrel to analyze oil field data, create maps and models, and interpret seismic data to better understand subsurface reservoirs. The document concludes with a case study using Petrel software to map horizons and faults in 2D and 3D seismic data from the GK-X Block in India.

1. SUMMER INTERNSHIP
ON
RESERVOIR ENGINEERING AND IT’S SOFTWARE
APPLICATION
AT
DIRECTORATE GENERAL OF HYDROCARBON
SUBMITED BY
HEMA SRIVASTAVA
M.Tech Petroleum Exploration
ISM Dhanbad.

2. INTRODUCTION
FUNDAMENTALS OF RESERVOIR ENGINEERING
A reservoir is a rock capable of holding gas, oil or water
For a reservoir to be commercially viable, it must be big and thick enough
Pore space capable of holding an appreciable volume of hydrocarbons
It must discharge the contained fluids at a satisfactory rate when the reservoir is
penetrated by a well.

3. PETRO-PHYSICAL PROPERTIES
Porosity
•
•
The porosity of a formation determines its capacity for a reservoir fluid
Porosity is defined as the relative amount of void space existing within a rock.

4. Types of pores

5. PRIMARY AND SECONDARY POROSITY
Primary porosity shows original porosity. It forms when sediments deposited.
Primary pores may be divided into two subtypes:
interparticle (or intergranular) and interaparticle
Intercrystalline porosity:
Fracture porosity:
Fracture may develop on the crests of anticline and the nadirs of syncline

6. fracture may develop adjacent to faults.
The relation between porosity and reservoir frequency.

7. PERMEABILITY
Permeability is a measure of a rock's ability to conduct fluids. Fig shows how the
permeability of a rock sample can be measured.
q = k (P1-P2)A/ µL
SATURATION
Saturation is defined as that fraction, or percent, of the pore volume occupied by a
particular fluid (oil, gas, or water). This property expressed mathematically by the
following relationship:
Fluid saturation = Total volume of the fluid / Pore volume

8. WETTABILITY
Wettability is defined as the tendency of one fluid to spread on or adhere to a solid surface
in the presence of other immiscible fluids.
Capillary Pressure
Consideration of the wettability of pores leads us to concept of capillary, the
phenomenon where by liquid is drawn up a capillary tube. The capillary pressure is
difference between the ambient pressure and pressure exerted by the column of liquid.
capillary pressure increases with decreasing tube diameter.
Cross- section of capillary tube /pores showing meniscus effect for (A) Oil-wet and (B)
water-wet reservoirs.

9. Methods of Reserves Estimation
The reserves can be estimated by the following methods:
1. Volumetric
2. Material balance
3. Numerical simulation models
4. Production decline curves
 Except for the volumetric method, all other methods rely on reservoir performance
data.
Well testing
Introduction
Types of Flows:
• Steady-state flow
• Unsteady-state flow
• Pseudosteady-state flow

10. Reservoir geometry:
The shape of a reservoir has a significant effect on its flow behavior.
● radial flow;
● linear flow;
● spherical and hemispherical flow
sphrical
SOFTWARE APPLICATIONS
OilField Manager is a surveillance software application that has been developed by
Schlumberger
OFM provides an intuitive, user-friendly interface enabling viewing, modification, and
analysis of production and reservoir data within the Microsoft® Windows environment .

11. Data from an oil field was compiled in an excel file and a base map was
created using OFM and then the following analyses were carried out:
1. Bubble Map
2. Map X-Y Plot
3. Contour Map
4. Surface Map
5. Grid Map
6. Scatter Plot
7. Logarithmic graphs.

12. Base map showing wells W-1 to W-10
Base map Bubble map

13. Map X-Y Plot
Cummulative Production Monthly Production

14. Logarithmic graphs
Well 1 Well 2

15. Well 6 Well 7

16. OVERVIEW OF PETREL SOFTWARE
Petrel is a Schlumberger owned Windows PC based software application intended
to aggregate oil reservoir data from multiple sources.
It allows the user to interpret seismic data, perform well correlation, build reservoir
models and, calculate volumes, produce maps and design development strategies to
maximize reservoir exploitation.
Advantages
Scalable interpretation at your desktop—to visualize and interpret data
Modeling-while-interpreting capability—to produce higher-quality interpretation by
building a structural framework in the background while you interpret
Improved volume interpretation—to identify and extract geological features.
Combines visual and performance advantages of 3D seismic interpretation with the
traditional 2D views for accuracy and detailed event picking, enabling advanced 3D
visualization at every desktop..
2D/3D Multi-Volume Interpretation
• It often happens to work with multi vintage data as well as both 2D and 3D seismic
data. Petrel software makes it easy to interpret both 2D and 3D data simultaneously
to get the best understanding of subsurface in the shortest time.

17. Seismic Interpretation Gk-X Block Of Gujarat-kutch Basin Using Petrel
Objective Of Project:
Mapping of three key stratigraphic units in 2D&3D seismic data of Gujrat-
Kutch basin. Comparing the maps with same age which were mapped in 2D
and 3D seismic data.
Project Area:
The GK-X Block is located in the Northern offshore part of Kutch basin. The
eastern boundary of the block is about 25km of the coast. It covers an area
of 1264sq.km.Water depth in the block varies from 5-35m.
Available Data:-
The block has been covered by 18 numbers of 2D seismic lines&48Osq.km.3D
seismic data. We have three wells named GK-X-A, GK-X-B, GK-X-C.

18. Seismic coverage map of GK-X Block

19. Seismic section with key horizon:
Interpreted 2Dseismic section
along a strike line 11
Interpreted 3Dseismic section
along a strike line 11

20. Two-way time (TWT) contour maps:
Three two-way time (TWT) contour maps corresponding to tops of three stratigraphic
levels were prepared:
Oligocene 2D Surface map Oligocene 3D map

21. Iso-chronopachs (Time thickness maps)
Eocene and Oligocene top Paleocene top and Eocene top

22. Comparison between 2D and 3D Maps:
Basin is thickening in the upper side both in the 2D and 3D.
Basin thinning is clear in 3D at down side’s right end but the basin thinning is not
clear in 2D.
Fault is missing in 2D because lack of data control and the fault which is very
evident in 3D dimension in Oligocene level. And as well as down throw of the
fault is also clear in 3D.
Seismic Interpretation
Generalized stratigraphy of Gujarat-Kutch Basin.
Generation of synthetic seismogram, making of Formation tops on well logs and
converting the depth data in to time domain using synthetic seismogram.

23. One major fault is identified and tracked, which runs across the area in the NW-SE direction
which was marked. Another minor fault in the area was also considered for mapping as that is
continuously seen for more than one or two lines in the area.
Horizon tracking using geophysical interpretation module in PETREL was effectively
completed for three markers.
Seismic surfaces of all the three marked horizons were generated including the faults.
.
Conclusion
1. By using petrel software observed that the mapping quality increases depending on the data
control.