DIRECTIONAL DRILLING MOTOR

Major Project Submitted

In partial fulfillment of the requirements

For the award of the degree of

 

MASTER IN TECHNOLOGY IN PETROLEUM EXPLORATION

BY

S.SURESH

(Reg.no. -709212345011)

DELTA STUDIES INSTITUTE

College of Science and Technology

Andhra University

Visakhapatnam

2010

DEFINITION

Controlled directional drilling is the science and art of deviating a wellbore along a planned course from a starting location to a target location, both defined with a given coordinate system.

Controlled Directional Drilling

Directional drilling was initially used as a remedial operation, either to sidetrack around stuck tools, bring the wellbore back to vertical, or in drilling relief wells to kill blowouts. Interest in controlled directional

Drilling began about 1929 after new and rather accurate means of measuring the hole angle were introduced during the development of the Seminole field, Oklahoma, USA.

HISTORY

Well Planning Introduction

Types of Wells:

•Exploration wells

•Appraisal wells

•Development or Production wells

Well Profile Terminology

A general classification of build rates is shown in Figure

Directional Drilling Bottom Hole Assemblies

How do we drill these crooked holes?

•Steerable Assemblies

•Rotary Assemblies

ROTARY ASSEMBLIES

Fluid Flow Path

•The stabilizer above the bit is removed & an additional collar is added making the bottom-hole assembly more flexible

•Gravitational forces acting on the bottom collar and bit, causing the hole to lose or decrease the angle

PENDULUM PRINCIPLE

FULCRUM PRINCIPLE•The fulcrum uses a stabilizer inserted into the drill string just above the bit

•With the bit rotating on bottom, enough weight is applied to cause the bottom collars to bow.

•In holes with 5° or more of inclination, the bow is towards the low side of the bow causes the bit against the top of the hole, resulting buildup.

NEW ERA OF AUTOMATIC DOWN-HOLE NAVIGATION

Rotary Steerable Systems•Allow drilling of smoother, more precise well paths than earlier.• Longer reach is possible• Ability to place wellbore through multiple targets greatly•improves recovery from single well

•Elimination of sliding and resulting friction•Less time spent on short trips and back reaming

ROTARY STEERABLE SYSTEM

•Rotating Shaft isdeflected in center between bearings with dual eccentric cams

• Results in bit tilt inopposite direction

MWD Tool is lowered along with the drill collar (Inclination, BAP, 3-axis Azimuthal Gamma, Resistivity tool, Pulser, Batteries

Latest Development for Rss

Further Developments for Geo-Pilot

IN-BIT TECHNOLOGY

• Box-up design allows room for instrumentation package

• Currently testing withvibration and temperature

RIG VISIT EXPERIENCE Rig E760M at GMDN site KG Basin Field Sequential order of BHA:

BitMud MotorStabilizerMull shoe subNon mag collars

Wells planned at site

BUILD-UP & HOLD DESIGN

First Case R > D2The maximum inclination angle max for type I trajectory is given by:

Second Case R < D2

Radius of curvature(R) build up section:

Measured length of build-up section Tangent Section

Where α = maximum inclination angle at the end of buildup section.

•Vertical length of tangent section: V2 – V1 = R1 x sin α

Horizontal displacement at end of tangent section:

D1 = R1 × (1-cosα)

Tangent Section:•Measured length of tangent section:

•Vertical length of tangent section:

V3-V2 = MD3× cosα

•Horizontal Displacement at end of the tangent section:

D2=D1+MD3 × sin α

•Total measured depth for type I wells: TMD= MD1 + MD2 + MD3

'S' TYPE WELL DESIGN

D3 > R1 + R2

D3 < (R1+R2)

Radius of curvature (R1) of build-up section:

Radius of curvature of drop-off section

Where, DOR = Drop off rate, degrees/100ft

D3 > R1 + R2

D3 < R1 + R2

Tangent section:Vertical depth at end of tangent section:For wells that return to vertical at end of drop-off

section:

For S-wells wells that partially drop angle and maintain a certain inclination to target,

V3 given by:

Measured length of tangent section:

Horizontal displacement at end of tangent section:

S-well that does not return to vertical

S-well that does not return to vertical

Y = R1 + R2 cosα2+( V5-V4)tan α2-D4

If

For S well that do not return to vertical, first calculate D3 D3 = D4 - (V5-V4) tan α2

Build-up Section

Measured length of build-up section

Where α1 = maximum inclination angle at end of build-up section

Vertical depth at end of the build-up section

For wells that return to vertical at end of drop-off section:

Tangent sectionVertical depth at end of tangent section:For wells that return to vertical at end of drop-off

section:

For S-wells wells that partially drop angle and maintain a certain inclination to target, V3 given by:

Measured length of tangent section:

Horizontal displacement at end of tangent section:

Drop-off section:Measured length of drop-off s wells that return to

vertical:

Where α2= maximum inclination angle at end of drop section

Total measured depth for s wells that return to vertical:

Measured depth at end of a partial drop section where the angle of inclination is maintained to target is given by:

Total measured depth at end of a S well where the angle of inclination is maintained to target

Calculation as per well data

Kick-off depth = 1,200 ft

Build-up rate = 2.0 degrees/100 ft

Drop-off rate = 3.5 degrees/100 ft

TVD at end of drop-off section (V4) = 8157 ft

Total horizontal displacement (D3) = 2136 ft

Final inclination angle in reservoir = zero degrees

Radius of curvature

Build-Up section

Also given D3 = 2,136 ftSince (R1+R2) is greater than D3, equation must be used for determining the maximum inclination angle αmax

Given that V4=8157ft, V1=1200ft

αmax = 19 degrees

•Kick-off pointV1=1,200ftMD1 = V1 = 1,200FT

Build-up section

Drop-off section

TMD=MD1+MD2+MD3+MD4+(V5-V4)For this well, V5=V4

D3=2,136ft (given)= Total hole displacement

Tangent section

INCLINATION OF A WELL

THE GYRO SURVEY TOOL

MUD LUBRICATED BEARING SECTION

COMPONENTS OF MOTOR

String Stabilizers

JARRING:

SALT DOME DRILLING

OFFSHORE MULTIWELL DRILLING

ONSHORE DRILLING TO OFFSHORE LOCATIONS

RELIEF WELLS

APPLICATIONS OF DIRECTIONAL DRILLING

DIRECTIONAL WELL APPLICATIONS

SIDE TRACKING INACCESSIBILITY

FAULT DRILLING DRILLING INTO SHALLOW OFFSHORE RESERVOIRS

HORIZONTAL WELLS EXTENDED REACH WELLS

SHORT MEDIUMLONG RADIUS WELLS MULTILATERAL WELLS

CONCLUSION

Directional drilling has become a very important drilling process. It has enabled producers all over the world to develop subsurface deposits that could never have been reached economically in any other manner. In this module, directional drilling was defined along with its technical calculations of directional well as well as the features of a well profile were also covered. The module also included information related to directional drilling motor and its components.