BASICS OF OIL AND GAS FOR

CIVIL ENGINEERS

Chennai Office

by

Varanasi Rama Rao

Contact:

ram7407@gmail.com

Preface

This Presentation has been compiled to give a quick overview of

the upstream facilities of Oil and Gas for Civil engineers joining

the industry without previous exposure to Oil and Gas industry.

The emphasis is on the onshore part of the industry.

This presentation is by no means a comprehensive description of

the Oil and Gas industry but will serve as basic guide to

appreciate the facilities and the complexities involved in the

design of the facilities.

Contents

1. Introduction

2. Facilities

3. Up stream Process Overview

4. Main Process section

5. Civil Scope

6. Typical Plot Plan

7. Interfaces

8. Important terminology

1. Introduction

Oil has been utilized for many thousand years in areas where oil is found in

shallow reservoirs. It was in 1859 colonel Edwin Drake drilled the first

successful oil well in the north-west Pennsylvania for the sole purpose of

producing oil. The well was less than 50m and can be called very shallow as per

the modern standards. However, the well produced a very good amount of oil.

At the end of 19th century, oil became the most essential fuel of our society.

Photo: Drake Well Museum Collection,

Titusville, PA

2. Facilities ( On shore and Off shore)

The Oil and Gas industry comprise of two streams known as Up stream and Down stream

The Up stream facilities are further classified as On shore facilities and Off shore facilities

Up stream Facilities:

The on shore/off shore oil facilities basically comprise of the following:

•Well heads ( Source of Oil and Gas).

•Gathering Manifold Stations and

•Central Processing Facilities ( which separate crude oil, gas and water)

Down stream Facilities:

The Down stream facilities basically comprise of:

• Refineries

Upstream

Downstream

Figure 1A

UP STREAM DOWN STREAM

Figure 1B

Typical onshore

wellhead

Schematic showing

how the multiphase

fluid consisting of oil,

gas and water reaches

well head

Figure 2

Figure 3

Off

shore

wells

On shore

well

Figure 4

The oil wells consists of a multiphase mixture of oil, gas and water.

The oil wells can be dug on the shore or off shore on the sea bed.

Hence the basic difference between on shore and off shore is that the

well head is in on the ground for on shore and on the sea bed for off

shore.

3. UP STREAM PROCESS OVERVIEW

Figure 5A

Figure 5B

4. Main process section

The main process section of upstream comprise of the following:

• Well heads

• Gathering Manifold stations

• Central Processing Facilities

Well heads:

The well head sits on top of the actual oil or gas well leading to the reservoir

as shown in the figures 2 & 3. A well head may also be an injection well which

injects gas and water to maintain the pressure levels.

Gathering manifold stations:

A gathering manifold station comprises of set of pipe lines and manifold

systems to which the oil or gas or a multiphase fluid consisting of oil, gas and

water is diverted from well head.

From Gathering manifold station the Oil or Gas or Multiphase fluid is sent to

Central production facilities for further processing. The purpose of setting

manifold station is to allow set up of production “ well sets” so that for a given

production level, the best reservoir utilization well composition ( gas, oil ,

water) etc. can be selected from the available wells

Figure 6

Gathering manifold- Photo-1

Gathering manifold –Photo 2

Figure 7

Flow line from

wellheads'To Central Processing facility

Control

Building

Metering area

Testing area

Gathering

Manifold area

Figure 8

Gathering Manifold station Block diagram

Central Processing Facility:

This is called as heart of the upstream facility. In this facility the crude

oil or gas is produced and sent to the down stream facilities like

Refinery for extracting all the by-product with in the crude.

Down stream by-products:

For oil crude some of the by-products are:

• Gasoline

•Jet fuel

•Diesel

•Petrol

•Kerosene

•Lube oil

•Bitumen

•Naphtha

•Polymers, etc

For Gas crude some of the by-products are:

• LNG

•LPG, etc

Inle

t facilitie

s

Separa

tion tra

ins

Gas

compression

Gas storage

and metering

Fro

m G

ath

erin

g M

anifo

ld s

tatio

ns

Crude Oil

storage

Crude Oil

metering

Power

generation

Produced

Water

Pig launcher

Pig launcher

Gas Pipe line

Oil Pipe line

Figure 9

Central Processing Facility- Block Diagram

5. Civil Scope ( Overview)

So far we have seen broadly the configuration of upstream facilities. Now let

us briefly discuss about the General scope of civil work in the up stream

facilities.

Please note that the scope described below contains only the main items

which appear almost in all kinds of projects related to up stream industry.

However, these are not the only items but there can be some more items

which are specific to a particular project.

Scope near Well heads ( On shore):

• Topographic Survey

•Geotechnical Investigation

•Grading and Paving

•Roads ( optional)

•Fencing of the well head area

•Pipe supports

•Mechanical Equipment foundations.

•Miscellaneous foundation for light poles, instrumentation items etc.

Scope in Gathering Manifold stations:

•Topographic Survey

•Geotechnical Investigation

•Grading and Paving

•Roads

•Fencing

•Manifold foundations

•Manifold shelters

•Metering equipment/skid foundations

•Mechanical Equipment foundations

•Pipe supports

• Minor Pipe racks ( optional)

•Test Separator foundations

•Control Building ( Optional)

•Fire water tank foundation ( Optional)

•Flange Pits ( Optional)

•Cable trenches

•Minor UG networks

•Miscellaneous foundations for lighting poles, instrumentation items etc.

Scope in Central Processing Facilities:

• Topographic Survey

•Geotechnical Investigation

•Grading and Paving

•Roads

•Fencing

•UG networks

•Pipe supports

•Pipe Racks

•Platforms

•Technological Structures

•Horizontal and Vertical Vessel foundations

•Heater foundations

•Flare foundations

•Skid foundations

•Pump foundations

•Compressor foundations

•Turbine and DG foundations ( in case power generation is required)

•Tank foundations

• Sub station Buildings

•Transformer foundations

•Over head line foundations

•Pits

•Cable trenches

•Control Buildings

•Non Plant buildings

•Shelters

•Sheds, etc.

In the above pages so many structures and foundations

corresponding to up stream equipment are mentioned but how the

equipments look like?

Please go through some of the photographs in the following pages

which are collected from various sources.

Figure 10- Horizontal Vessel

Pipe

support

Pipe rack

Vertical

Vessel Figure-11

Figure 12 – Tank founded on ring wall

Manifold shelter, small vertical

vessel

Pipe sleepers

Figure 13

Figure 14 – Separation train ( partial view)

SHELTER

PITS

Figure 15

Figure 16

SKID

TECH STR.

Figure 17

Figure 18- Gas Turbine Generator ( GTG)

Figure 19- Flare

Guyed flare

Self supporting flare

Cooler

supported on

a pipe rack

Figure 20

Heater

Figure 21: Control Building and Telecom tower

Figure 22- Flow lines coming from gathering manifolds

Figure 23- Diesel Generators

Figure 24: Metering Skid

Figure 25: Pipe lines for carrying crude/Gas to Downstream

Figure 26: Slug Catcher

Figure 27: Burn Pit

6. Typical Plot plan

Figure 28

Inlet facilities

Crude oil

Storage area

Separation

train area

Produced

water area

Metering and

pumping

area

Gas

compression

area

Sub-station

building

Control room

Pipe racks

Figure 29- Typical 3D model of a Central Processing Facility

7. Interfaces

Civil

Instrumentation

Process

Projects

Construction

Electrical

PipingMechanical

Procurement

Frequent

interaction

8. Important Terminologyi. PFD( Process flow diagram): schematically shows all major equipment

items and how they are linked together by piping ducts and conveyors.

ii. Equipment list: An itemized accounting list by class of all equipments to be

used in a project

iii. P&ID ( Piping and Instrumentation Diagram): schematically shows all

process utility and auxiliary equipment as well as piping, valves

&instrumentation.

iv. Plot plan: is an arrangement drawing that highlights the equipment and

supporting facilities coming in a process plant

v. UG ( Underground network): All the arrangement corresponding to

drainage facilities in a plant is called Underground network.

vi. Pipe rack: A 3D frame supporting the piping

vii. Pipe Support: a 2D frame/ or T supporting piping

viii. Pipe sleeper: A concrete base supporting a pipe

ix. Equipments: Are generally, Horizontal and Vertical Vessels, Pumps,

Compressors etc. which require only a foundation to be designed by Civil

x. Skids: are steel frames on which equipments or set of equipments are

mounted

Frequently used abbreviations:

•FGL: Finished Ground Level

•NGL: Natural Ground Level

•TOC: Top of concrete

•TOG: Top of Grout

•TOS: Top of Steel

•BBS: Bar Bending Schedule

•GA: General Arrangement

•EL: Elevation

•BL: Battery Limit

•UG:Underground

•U/S: Under side

•BBP: Bottom of base plate

•POS: Point of Support

Thank youDisclaimer: This document is a free online resource prepared by a

professional based on his understanding and it is intended only for the

purpose of having an overview. The content in the document should not

be used and referred for any professional purpose. The author doesn’t

guarantee the authenticity of the information presented in the document.