BRIEF INTRODUCTION TO UPSTREAM INDUSTRIES AND PRESENT INDIAN SCENARIO

India’s only Energy Company in Fortune’s ‘World’s Most Admired’ List

EXPLORATION CYCLE• The following methods are sequentially used in the exploration for crude oil and

gas

Introducton to Petroleum Exporation2

Gravity / Magnetic Surveys

Geological Field Mapping/ Remote Sensing

Seismic Data API (2D/3D)

Prospect Identification

Drilling

Reservoir Studies

Production

Well Logs & VSP

BHS &

Simulation

GEOLOGY

Even where the organic matter can become mature, not all of it becomes petroleum.

In a typical case a normal marine shale with only 1% original organic matter will

have less than a third of it converted to the hydrocarbon molecules that make up oil

and natural gas (Waples, 1981).

The rest remains behind as an insoluble organic residue

GEOLOGY

• However, the least efficient step is yet to come.

• Of all the petroleum generated, only a small part, usually less than 1%

(Hunt, 1977), is able to undergo migration out of the source bed to

accumulate within a porous and permeable reservoir.

• The majority of petroleum, or even in some cases all of it, will be

dispersed for lack of a good arrangement of strata to trap it, or will leak

out to the surface, for lack of a good impermeable seal or caprock.

GEOLOGY

• If any one of these factors is missing or inadequate, the prospect

will be dry and the exploration effort will be unrewarded.

• Not surprisingly then, less than half of the world's explored

sedimentary basins have proved productive (Huff, 1980) and

typically only a fraction of 1% of the petroleum basin's area, and at

most 5% to 10%, is actually prospective (Weeks, 1975).

GEOLOGY

• A trap is a geometric configuration of structures &/or strata, in which permeable rock types (the reservoir) are surrounded & confined by impermeable rock types (the seal).

• Most traps fall into one of three categories: structural traps, stratigraphic traps, or combination traps

STRUCTURAL TRAP

STRATIGRAPHIC TRAP

Geological inputs

• Remote Sensing

• Geological map

• Cross section

• Sediment thickness

• Type of fill

• Subsidence history

GEOPHYSICAL DATA ACQUISITION

Data Acquisition

Data Interpretation

&

Data Processing

Reservoir Estimation

GEOPHYSICAL DATA ACQUISITION

Layering of sediments above

the earth’s surface can be

seen from Geological outcrops

But how do we “see” the

picture that is hidden below?

ANTICLINE

Anticline Outcrop (Cross Section View)

GEOPHYSICAL DATA ACQUISITION

• Seismic surveys allow geophysicists to see beneath the surface and map areas that are not visible.

On land Seismic Data Acquisition

Offshore Seismic Data Acquisition

Pre-drilling Inputs

Prospecting

Geological

Geophysical

Geochemical

Geological mapping &

traversing

Gravity, Magnetic &

Seismic

Geobotanical Microbial survey

geophysical prospecting

Gravity prospecting includes measuring a field of forcein the earth that is not generated by the observer. TheField instruments are designed to measure differencesin gravity. The Variation in gravity depend on lateralchanges in the density of earths materials. Mostsedimentary rocks have densities lower than basementrocks, make possible to map boundaries and determineapproximate depth distribution of sedimentary basins.

Magentic prospecting gives information to determinethe depth to basement rocks to locate and defineextent of sedimentary basins. The Sedimentary rocksexert small magnetic effects compared to igneousrocks. All variations in magnetic intensity measurableat surface result from topographic or lithologic changesassociated with basement or igneous intrusives

geophysical prospecting

• The seismic methods for exploration utilizes the fact that the reflecting surfaces between two rock beds have different lithology and density. The main purpose is to know depth of subsurface sedimentary beds and their alignment and structure like horizontal beds, inclined beds, folds faulted beds etc. Sound energy is either generated through a dynamite blast within a shot hole or a vibrater or a airgun (in case of marine surveys). The elastic waves (P-waves or primary waves) while propagating through sedimentary beds, part of energy will bounce back whenever they strike boundaries of rock beds having different densities of hardness. These reflections are received by geophones which in turn recorded along with time of their arrival which is called seismogram.

Geochemical Modelling

Surface & subsurface seeps

Organic richness of sediments

Thermal history

Identification of maturation window

Requirements for exploring a Basin

• Geological map

• Cross section

• Sediment thickness

• Type of fill

• Sequence

stratigraphic model

• Subsidence history

Surface & subsurface

seeps

Organic richness of

sediments

Thermal history

Identification of

maturation window

Identification of reservoir facies

Seal integrity

Possible traps

Migration paths

It is the science / art of making hole or bore in anobject.

Since we are concerned withpetroleum, so we can define drilling as a science ofmaking a hole in earth’s crust (called as an oil / gaswell) down to a desired depth in search ofpetroleum (oil or gas).

DRILLING

DRILLING

To study the science of drilling we have to divideit into two categories:

Drilling Engineering.

Drilling Technology

PRODUCTION, PROCESSING & TRANSPORTATION

Well FluidProcessing

Tankage

Value Addition

Well Completion.

Well Testing.

Well Stimulation.

Artificial Lift Systems.

Workover Operations.

Oil/Gas processing.

Pressure maintenance.

Production Activities

Operation & Maintenance of

Production facilities & pipelines.

Production of Value Added

Products.

Transportation of Oil/Gas.

Design/Construction of

Onshore/Offshore Production

Facilities.

Production Activities

Effective Gas utilisation.

Short/Long term production

plans and implementation.

Implementation of EOR

schemes.

Safety in Production

Operations.

Production Activities

ARTIFICAL LIFT

ENHANCED OIL RECOVERY

ENHANCED OIL RECOVERY

SEDIMENTARY BASIN

• “An unit of lithosphere which subsided as a function of time and received sedimentary succession unique to it.”

More than 600 basins- identified globally.

Active hydrocarbon exploration - in about 400 basinsworld wide.

About 180 basins- under commercial production.

The ultimate H/C resources of the world - about 620billion tonnes.

85% of reserves - confined to only in 30 basins.

INDIA

• India is having vast

land area covered

with sedimentary

rocks.

• Geologically they

are subdivided into

26 sedimentary

basins covering

about 3.14 million

sq. km.

Indian Sedimentary Basins

1958: Cambay Basin

1967: Rajasthan Basin

1889: Assam Shelf

1974: Mumbai Offshore

1980: KG Basin

1973: A&AA FB

1985: Cauvery Basin

Out of 26 Basins 7 are petroliferous