INTRODUCTION TO GEOTHERMAL DRILLINGagid.theargeo.org/reports/UNU-GTP2019/Short course... · A drilling rig is an equipment that is used for drilling geothermal...

Sustainable Development Goals Short Course III on Exploration and Development of Geothermal Resources

George Moshe Dayan, Drilling Engineer-KenGen

INTRODUCTION TO GEOTHERMAL DRILLING

23rd November 2019

SDG Short Course IV on Exploration and Development of Geothermal ResourcesOrganized by UNU-GTP and KenGen | Lake Bogoria and Lake Naivasha | Nov 14-4 Dec, 2019

OUTLINE

Drilling Rigs

Introduction

2

3

1

4 Drilling Contracts

5 Personnel

Drilling Plan


INTRODUCTION

•Geothermal well drilling is the process of making a hole in the earth to extract thermal energy from the earth’s crust.

• It normally takes 55-65 days to drill to 3000m at an approximate cost of USD 5 Million


INTRODUCTION CONT’D-TYPES OF WELLS

•Exploration wells-can be slim holes/gradient holes

•Appraisal wells-

• Production wells

• Re-injection wells

•Make-up wells

•Work-over


INTRODUCTION CONT’D-DRILLING PHASES


DRILLING RIGS

A drilling rig is an equipment that is used for drilling

geothermal wells:Electrical,mechanical,Hydraulic-Perfoms the

following:

•Hoisting-Hold the drill string and apply weight on the bit

• Rotation- provide rotary motion to the drill bit

• Circulation- flush out drilled cutting out of the hole


DRILLING RIGS- DRILL STRING COMPONENTS

•Bit

•Mud motor

•Bit sub

• Stabilizers/reamers

•Cross over

•Collars/monel

•Heavy weight Drill pipe/drill pipes


DRILLING PLAN

•Quality-Targeted resource, reservoir quality, life of the well

•Cost-Optimizing of costs(key in keeping electricity costs

down)

• Safety/Environment management-Ensure safety of

personnel,equipment,environment


DRILLING PLAN- DRILLING PROGRAM

Prepared by a drilling engineer ,main contents include:

• Well Prognosis-Provided by the geologist

• Rig/equipment information

• Casing Design

• Bit Design

• Drilling fluid Program

• Waste management/EMP


DRILLING PLAN- WELL DESIGN

The design of a geothermal well entails the following key

aspects:

• The purpose of the well/targeted resource

• Type of the well; vertical or directional

• Reservoir conditions- pressures, temperature

•Existing surface or shallow hole conditions

•Anticipated drilling challenges

• Casing requirements


DRILLING PLAN- WELL DESIGN


DRILLING PLAN- SPECIALIZED SERVICES

•Directional drilling

•Cementing

• Stuck pipe and fishing

•Drill pipe inspection


DRILLING CONTRACTS

An operating company may hire a contractor to drill the well. Different

types of contracts may be entered into:

• Day rate contracts.

• Modified day rate (footage bonus) contracts:

• Footage contracts:

• Turnkey contracts


RIG PERSONNEL


INFORMATION

Name of course: SDG Short Course III on Exploration and Development of Geothermal Resources

Location: Lake Bogoria and Lake Naivasha, Kenya

Timing: November 14-December 4, 2019

Organized by: United Nations University Geothermal Training Programme (UNU-GTP) and Kenya Electricity Generating Company (KenGen)

Financed by: UNU-GTP and KenGen

Presentation author(s): George Moshe Dayan ([email protected])

KenGen Plc

P.o Box 784 20117 Naivasha Kenya

www.kengen.co.ke

INTRODUCTION TO GEOTHERMAL DRILLINGagid.theargeo.org/reports/UNU-GTP2019/Short course... · A drilling rig is an equipment that is used for drilling geothermal...

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