Introduction to Directional Drilling

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Introduction to Directional Drilling Revised: 6/13/01 Page 1 of 52 Introduction to Directional Drilling Subject Matter Experts: Raymond de Verteuil and Iain McCourt Sugar Land Learning Center 1998, revised 2001 An asterisk (*) is used throughout this module to denote a mark of Schlumb erger Copyright Schlumberger Technology Corp., unpublished work, created 1998, reviewed 2001. The following material includes Confidential, Proprietary Information and is a trade secret of Schlumberger Technology Corp. All use, disclosure, and/or reprod uction is prohibited unless authorized in writing. All rights reserved. This material may also be protected under laws of non-U.S. countries, including copyright and trade secret laws. Source: IntroToDD.pdf, Revised 6/13/01, SLC

Transcript of Introduction to Directional Drilling

Introduction to Directional Drilling Revised: 6/13/01 Page 1 of 52

Introduction to Directional Drilling

Subject Matter Experts: Raymond de Verteuil and Iain McCourt

Sugar Land Learning Center

1998, revised 2001

An asterisk (*) is used throughout this module to denote a mark of Schlumb erger Copyright Schlumberger Technology Corp., unpublished work, created 1998, reviewed 2001. The following material includes Confidential, Proprietary Information and is a trade secret of Schlumberger Technology Corp. All use, disclosure, and/or reprod uction is prohibited unless authorized in writing. All rights reserved. This material may also be protected under laws of non-U.S. countries, including copyright and trade secret laws.

Source: IntroToDD.pdf, Revised 6/13/01, SLC

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Source: SLC IntroTo DD.doc Revised: 10/20/98 6:37 AM

Objectives

In this module you will learn to do the following:

1. Define directional drilling by choosing the correct answer from a list of selections.2. Recall the historical development of directional drilling by choosing the correct answer from

a list of selections.3. Recognize the reasons for drilling the following types of wells: exploration, appraisal,

development/production.4. Identify descriptions and pictures of directional drilling applications.5. Identify several features of a directional well profile.6. Identify the general types of directional well profiles.7. Recall an explanation of a well plan by choosing an answer from a list of selections.8. Identify the basic components of a well plan.

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1 IntroductionDirectional drilling has become a very important tool inthe development of oil and gas deposits. Currentexpenditures for hydrocarbon production have dictatedthe necessity of controlled directional drilling to a muchlarger extent than previously.

Probably the most important aspect of controlleddirectional drilling is that it enables producers all overthe world to develop subsurface deposits that couldnever be reached economically in any other manner.In this module a number of topics will be covered thatmust be understood by the directional driller. Thevarious types of wells and applications of directionalwells will be touched upon along with well profiles andwell planning.

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2 Directional Drilling

In this lesson you will learn to do the following:

Define directional drilling by choosing the correct answer from a list of selections. Recall thehistorical development of directional drilling by choosing the correct answer from a list ofselections.

2.1 Definition of Directional Drilling

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

2.2 Description of Directional Drilling

Drilling a directional well basically involvesdrilling a hole from one point in space (thesurface location) to another point in space(the target) in such a way that the hole canthen be used for its intended purpose.

A typical directional well starts off with avertical hole, then kicks off so that thebottom hole location may end up hundreds orthousands of feet or meters away from itsstarting point.

With the use of directional drilling, several wells can be drilled into a reservoir from a singleplatform.

2.3 Historical Development ofDirectional Drilling

Directional drilling was initially used as aremedial operation, either to sidetrackaround stuck tools, bring the wellbore backto vertical, or in drilling relief wells to killblowouts.

Interest in controlled directional drillingbegan about 1929 after new and ratheraccurate means of measuring the hole anglewere introduced during the development of

the Seminole field, Oklahoma, USA.

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Historical Development of Directional Drilling

In 1930, the first controlled directional well was drilled inHuntington Beach, California, USA. The well was drilledfrom an onshore location into offshore oil sands.

Controlled directional drilling had received ratherunfavorable publicity until it was used in 1934 to kill a wildwell near Conroe, Texas, USA. As a result, directionaldrilling became established as one way to overcome wildwells, and it subsequently gained favorable recognition fromboth companies and contractors.

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Study Questions

1) Which of the following is the correct definition for directional drilling?

a) The science and art of deviating a wellbore along a planned course to a surface targetlocation that is a given lateral distance and direction from the horizontal

b) The science and art of deviating a wellbore along a planned course to a subsurface targetlocation that has not been Determined

c) The science and art of deviating a wellbore along a planned course to a subsurface targetlocation that is a given vertical distance and direction from the horizontal

d) The science and art of deviating a wellbore along a planned course from a surfacelocation to a target location, both defined with a given coordinate system

2) Which of the following is the most important aspect of controlled directional drilling?

a) It enables producers all over the world to develop subsurface deposits that could never bereached economically in any other manner.

b) It is the science of deviating a wellbore along a planned course to a surface target locationthat is a given lateral distance and direction from the horizontal.

c) It enables producers all over the world to develop subsurface deposits that could havebeen lost due to improper drilling equipment.

d) It enables producers all over the world to kill wild wells.

3) Directional drilling was used initially for remedial operations. Which of the followingare examples of these earlier uses? Select all the correct answers.

a) To drill relief wells to kill blowoutsb) To sidetrack around stuck toolsc) To bring the wellbore back to verticald) For salt dome drillinge) For offshore multiwell drilling

4) Where was the first controlled directional well drilled in 1930?

a) Conroe, Texasb) Huntington Beach, Californiac) Seminole field, Oklahomad) Long Beach, California

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3 Types of Wells

In this lesson you will learn to do the following:

Recognize the reasons for drilling the following types of wells: exploration, appraisal,development/production.

3.1 Three General Types of Wells

Wells are generally classified asexploration wells, appraisal wells,and development wells/productionwells.

Exploration wells, sometimes calledwildcat wells, probe the earth whereno known hydrocarbons exist todetermine whether oil or gas arepresent in a subsurface rockformation.

Appraisal wells are drilled to determine the extent of a field or the amount of area it covers.

Development or Production wells are drilled in an existing field to remove the obtainablehydrocarbons.

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Study Questions

1) Exploration wells are drilled for which of the following reasons? Select all the correctanswers.

a) To produce an existing fieldb) To determine the extent of a fieldc) To determine whether oil or gas exists in a subsurface rock formationd) To probe the earth where no known hydrocarbons existe) To reach a reservoir that is in excess of 15,000 ft

2) Appraisal wells are drilled for which of the following reasons? Select all the correctanswers.

a) To determine the extent of a fieldb) To probe the earth where no known hydrocarbons existc) To produce an existing fieldd) To determine how much area a field coverse) To reach a reservoir that is in excess of 15,000 ft

3) Development wells/Production wells are drilled for which of the following reasons?

a) To probe the earth where no known hydrocarbons existb) To remove hydrocarbons from an existing fieldc) To determine the extent of a fieldd) To reach a reservoir that is in excess of 15,000 ft

4) Match each well with its reason for being drilled.

a) To determine whether oil or gas exists in a subsurface rock formationb) To remove hydrocarbons from an existing fieldc) To determine the extent or area of coverage of a field

1) Exploration wells2) Development wells/Production wells3) Appraisal wells

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4 Directional Well Applications

In this lesson you will learn to do the following:

Identify descriptions and pictures of directional drilling applications.

4.1 Sidetracking

Sidetracking was the original directionaldrilling technique used to get past fish(obstructions). Oriented sidetracks, the mostcommon type of sidetracking, are performedwhen there are unexpected changes ingeology and obstructions in the path of thewellbore.

4.2 Inaccessible Locations

Inaccessible locations such as targets locatedbeneath cities, rivers or environmentallysensitive areas make it necessary to locatethe drilling rig some distance away from thetarget.

4.3 Salt Dome Drilling

Salt domes have been found to be naturaltraps of hydrocarbons accumulating beneaththe overhanging hard cap. A directional wellis used to reach the trapped reservoir toprevent the problems associated with drillinga well through the salt formation.

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4.4 Fault Controlling

Fault controlling is an application used todrill a directional well into faulted subsurfaceformations without crossing the fault line.

4.5 Multiple Exploration Wells from ASingle Wellbore

Multiple exploration wells from a singlewellbore use a single hole to drill multiplenew wells by deviating away from theoriginal well at a certain depth. It allows theexploration of structural locations withoutdrilling another complete well.

4.6 Onshore Drilling to OffshoreLocations

Onshore drilling takes place when a reservoiris located below large bodies of water thatare within drilling reach of land. Thewellheads are located on land, and theborehole is drilled directionally underneaththe water to reach the reservoir. Thistechnique saves money because land rigs aremuch cheaper than offshore rigs.

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Study Questions

1. Which of the following are reasons for drilling a directional well? Select all the correctanswers.

a) To get to trapped oil beneath salt domesb) To get to a target located beneath a city or a sensitive areac) To get past a fishd) To reach a reservoir located below large bodies of watere) To allow for exploration without drilling other complete wells

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4.7 Offshore Multiwell Drilling

Offshore multiwell drilling is the mosteconomical way to develop offshore fields.Several directional wells are drilled in"clusters" on a multiwell offshore platform.

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Study Question

2) Which of the following directional drilling applications is the most economical way todevelop an oil field that is below a large body of water but within drilling reach of land?

a) Offshore multiwell drillingb) Offshore drilling to onshore locationsc) Onshore drilling to offshore locationsd) Multiple exploration wells from a single offshore wellbore

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4.8 Relief Wells

Relief wells are used to kill wells that areblowing by intercepting the borehole. Acarefully planned directional well must bedrilled with great precision to locate andintercept the blowing well’s borehole.

4.9 Horizontal Wells

Horizontal wells are used to intersect aproducing formation horizontally to betterproduce the reservoir. Horizontal drillingincreases the surface area of a producingformation. For example, a vertical well maygive exposure to a reserve with a depth of 20to 30 ft (6 to 10 m) while a horizontal welldrilled into the same reservoir may giveexposure to 2000 to 3000 ft (600 to 1000 m).Horizontal wells can make a platformprofitable, where it was not previously.

4.10 Extended Reach Wells

Extended reach wells are drilled to reachreservoirs that have a horizontaldisplacement in excess of 16,400 ft (> 5,000m) from the starting point.

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4.11 Multilateral Wells

Multilateral wells have several wellboresrunning laterally and originating from oneoriginal hole.

4.12 Short, Medium, and Long RadiusWells

Short radius wells, typically re-entries of oldvertical wells, have curves with a 143 ft (44m) radius or smaller that cannot be drilledwith conventional motors. They are used toisolate higher-/lower-pressured productionzones or water sands without setting andcementing a liner. This type of drilling isdesirable when kicking off below a problemformation.

Medium radius wells have curves with a 200-500 ft (61-152 m) radius that can be drilled withconventional motors.

Long radius wells have curves with a 750 ft (229 m) radius or larger that can also be drilled withconventional motors.

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Study Questions

3) Which of the following are applications for drilling a directional well? Select all thecorrect answers.

a) Onshore drilling to offshore locationsb) Relief wellsc) Offshore multiwell drillingd) Horizontal wellse) Multiple exploration wells from a single wellbore

4) Which of the following are applications for drilling a directional well? Select all thecorrect answers.

a) Sidetrackingb) Salt dome drillingc) Offshore drilling to onshore locationsd) Fault controllinge) Inaccessible locations

5) Which of the following is the best description of a directional drilling application that isused specifically to kill a well that is blowing?

a) Salt dome drillingb) Horizontal wellsc) Offshore multiwell drillingd) Relief wells

6) Which of the following is the best description of a directional drilling application that isused specifically to intersect a producing formation horizontally to better produce thereservoir?

a) Onshore drilling to offshore locationsb) Offshore multiwell drillingc) Horizontal wellsd) Relief wells

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7) Identify each picture with its directional drilling application.

a) Sidetrackingb) Inaccessible locationc) Salt dome drilling

8) Identify each picture with its directional drilling application.

a) Onshore drilling to offshore locationb) Fault controllingc) Offshore multiwell drilling

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9) Identify each picture with its directional drilling application.

a) Horizontal wellb) Multilateral wellc) Relief well

10) Identify each picture with its directional drilling application.

a) Extended reach wellsb) Fault controllingc) Short radius wells

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11) Extended reach wells are drilled to reach reservoirs that are inexcess of _____ meters from the starting point.

a) 500,000b) 5,000c) 500d) 50

12) Which of the following would apply to short radius directional drilling? Select all thecorrect answers.

a) Used to isolate higher-/lower-pressured production zones or water sands without settingand cementing a liner

b) Typically reentries of old vertical wellc) Has curves with a 200 to 500 ft radiusd) Has curves with a 143 ft radius or smaller that cannot be drilled with conventional motors

?

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5 Directional Well Profiles

In this lesson you will learn to do the following:

Identify several features of a directional well profile.Identify the three general types of directional well profiles.

5.1 Features of A Directional Well Profile

A directional well profile is the planned well trajectory from the surface to the final drillingdepth by projecting the wellbore onto two plotted planes. In order to determine the bestgeometric well profile from the surface to the bottomhole target, the following information mustbe known

• the position of the surface location,• the position of the target location, and• the true vertical depth (TVD).

A directional well profile is the planned welltrajectory from the surface to the finaldrilling depth by projecting the wellbore ontotwo plotted planes. In order to determine thebest geometric well profile from the surfaceto the bottomhole target, the followinginformation must be known the position ofthe surface location, the position of the targetlocation, and the true vertical depth (TVD).

A directional well profile is the planned welltrajectory from the surface to the finaldrilling depth by projecting the wellbore ontotwo plotted planes. In order to determine thebest geometric well profile from the surfaceto the bottomhole target, the followinginformation must be known the position ofthe surface location, the position of the targetlocation, and the true vertical depth (TVD).

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5.1.2 Kickoff Point (KOP)

The kickoff point is the location at a givendepth below the surface where the wellboreis deviated in a given direction.

5.1.3 Well Inclination

The well inclination is the angle by whichthe wellbore deviates from the vertical.

5.1.4 End of Buildup (EOB)

The end of buildup is the location where thewellbore has finished increasing.

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5.1.5 Hold Angle

The hold angle occurs where the inclinationof the borehole is held constant.

5.1.6 Tangent Section

The tangent section (hold section) occursafter a buildup where the inclination of theborehole is held constant for a certaindistance. There could be an additional buildor drop before reaching the target.

5.1.7 Start of Drop

The start of drop is the location where thewellbore starts dropping inclination.

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5.1.8 End of Drop (EOD)

The end of drop is the location where thewellbore finishes dropping inclination.

5.1.9 Target Displacement

The target displacement is the lateraldistance from the surface location to thetarget.

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Study Question

1) Write in the correct term to correctly complete the following sentence.

A well profile is the planned well trajectory from the ____________________ to the finaldrilling depth.

2) Which of the following must be known to determine the best geometric well profilefrom the surface to the bottomhole target? Select all the correct answers.

a) The TVD of the targetb) The position of the surface locationc) The position of the target locationd) The density of the target

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5.1.10 Target Location

The target location is a point defined in spaceby geographical coordinates at a given truevertical depth. A well profile could havemultiple targets.

5.1.11 Drop Off Rate (DOR)

The drop off rate is the rate at which theinclination decreases. The rate is usuallyexpressed in degrees per 100 ft or degreesper 30 m of the course length.

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Study Question

3) Identify the features of a directionalwell profile.

a) Surface Locationb) Tangent Sectionc) KOPd) Hold Anglee) Target Location

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5.1.12 Buildup Rate (BUR)

The buildup rate is the change of inclination of a wellbore where the angle is increased. The rateis usually expressed in degrees per 100 ft or angular increase per 30 m of the measured depth.

5.1.13 Turn Rate

The turn rate determines the rate a well profile turns in azimuth direction. Usually expressed indegrees per 100 ft or degrees per 30 m.

True Vertical Depth (TVD)

The true vertical depth ofany point or station along awellbore is the verticaldistance from the wellsurface reference point tothe station of interest.

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Measured Depth (MD)

The measured depth of anypoint or station along awellbore is the distancefrom the well surfacereference point to thestation of interest along theactual well path.

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Horizontal Displacement(HD)

The horizontal displacementis the distance between anytwo points along a wellboreprojected onto a horizontalplane or plan view.

Vertical Section (VS)

The vertical section is the distancebetween any two points along awellbore projection onto a verticalsection plane.

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Azimuth

The azimuth is the angle inthe horizontal planemeasured from a fixedreference direction (such asTrue North), usuallymeasured clockwise.

5.1.19 QuadrantThe quadrant bearing of a well is the angle inthe horizontal plane measured from either aNorth or South reference direction towardsthe East or West, defining the direction of thewellbore.

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5.1.20 Polar Coordinate

The polar coordinate of a point is thedistance projected in a horizontal plane froma fixed reference point and the angle of thisline from a reference direction (usually TrueNorth).

5.1.21 RectangularCoordinate

The rectangularcoordinates of a point aredefined as the projecteddistance along tworeference axes which areat right angles, thedistance being measuredfrom the intersection ofthe axes along the axes.These axes reside in thehorizontal plane andtypically are north/southand east/west directions.

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Study Questions

4) Match each well profile feature with its definition.

a) The geographical position on earth where the well startsb) The location at a given depth below the surface where the wellbore is deviated in a given

directionc) The change of inclination of a wellbore where the angle is increasedd) Determines the rate a well profile turns in azimuth direction

1) Kickoff Point2) Surface Location3) Buildup Rate4) Turn Rate

5) Match each well profile feature with its definition.

a) Occurs where the inclination of the borehole is held constantb) The location where the wellbore starts dropping inclinationc) The angle by which the wellbore deviates from the verticald) The change of inclination of a wellbore where the angle is purposely reduced

1) Well Inclination2) Drop Off Rate3) Hold Angle4) Start of Drop

6) Match each well profile feature with its definition.

a) The actual measured vertical depth from a reference point on the surface to a point ofinterest

b) The lateral distance from the surface location to the targetc) Direction of a course measured in a clockwise direction from 0-360o referred to Northd) The length of the projection of the horizontal displacement onto the vertical section plane

defined by its azimuth.

1) True Vertical Depth2) Target Displacement3) Vertical Section4) Azimuth

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7) Match each well profile feature with its definition.

a) The actual length of the wellbore from its surface location to any specified stationb) The distance between two points that are projected onto a horizontal planec) A point where a well profile finished dropping inclinationd) The point or location of the oil and gas reservoirs

e) Measured Depthf) Targetg) Horizontal Displacementh) End of Drop

6) Match each well profile feature with its definition.

a) Occurs after a buildup where the inclination of the borehole is held constant for a certaindistance

b) The azimuth angle measured from North or South in the direction of East or Westc) A point defined by a distance and a direction relative to Northd) Used to give a target's position in feet or meters with direction of North/South and

East/Weste) The location where the wellbore has finished increasing

1) Tangent Section2) Polar Coordinate3) Rectangular Coordinate4) Quadrant5) End of Buildup

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5.2 Types of Directional Well Profiles

In general, directional wells can be either:

• Straight (Vertical),• S-type,• Slant (J-type), or• Horizontal.

The type of profile selected will depend upon the geological objectives and the productionmechanism of the well.

5.2.1 Straight Well (Vertical)

Straight wells have a bore with no planneddeviation from vertical.

5.2.2 S-Type Well

S-type wells have a bore with a straightsection, a build section, a tangent section,and a drop section.

This type of well is drilled to improve theefficiency of the well and to assist in thelocation of a blown-out well. In offshoredrilling, S-type wells can ensure accuracy inbottomhole spacing when multiple wells aredrilled from the same platform.

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5.2.3 Slant Well (J-Type)

Slant wells, sometimes called J-type wells,have a bore with a straight section, a buildsection, and a tangent section straight to thetarget

Slant or J-type wells are drilled where it isnot desirable or possible to locate the surfacelocation directly above the target or amultiwell platform.

5.2.4 Horizontal Well

Horizontal wells have a bore with a straightsection, a build section, tangent section, asecond build section (most of the time), anda horizontal section.

The well is drilled to a point above thereservoir; then it is deflected and the angleincreases until it reaches 90 degrees or more.When properly applied, one horizontalborehole can produce a reservoir better thanseveral vertically drilled wells.

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Study Questions

8) Match each well profile feature with its definition.

a) Occurs after a buildup where the inclination of the borehole is held constant for a certaindistance

b) The azimuth angle measured from North or South in the direction of East or Westc) A point defined by a distance and a direction relative to Northd) Used to give a target's position in feet or meters with direction of North/South and

East/Weste) The location where the wellbore has finished increasing

1) Tangent Section2) Polar Coordinate3) Rectangular Coordinate4) Quadrant5) End of Buildup

9) Which of the following are general types of directional well profiles? Select all thecorrect answers.

a) Straightb) Slantc) S-typed) Horizontal

10) This graphic represents which of thefollowing types of directional wellprofiles.

a) Straight wellb) Horizontal wellc) S-type welld) Slant well

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6 Well Planning

In this lesson you will learn to do the following:

Recall an explanation of a well plan by choosing an answer from a list of selections. Identify thebasic components of a well plan.

6.1 Definition of A Well Plan

Well planning is an organized process used to puttogether data that will be used to design a successfulwell. A well plan is a very important stage prior to thecommencement of the drilling operation to ensure thatall aspects are tailored to meet the specific objectivesof that well. Anadrill well plans are often developed ina Drilling Engineering Center (DEC) by a well planner.

Understanding how to design a well plan (proposal), isone of the most important duties of the directionaldriller. He must be able to understand the plan andmake any required changes.

The data provided by the client is used by the well planner to develop a geometric profile for thesafest and easiest path from the surface location to the target. The planner has access to acomputer program to help develop the best possible profile. The needed data is put into theprogram so that a well profile can be printed, plotted and used for the drilling project.

6.2 Components of a Well Plan

There are many components to take into consideration when designing a successful well plan.The well planning components listed here are the same as the features of a well profile found insection 5.1. If you do not recall these terms, please refer back to section 5.1.

Components of a Well Plan

• Surface Location• Target Location• Kickoff Point• Buildup Rate• Turn Rate• Hold Angle• Start of Drop• True Vertical Depth• Target Displacement• Azimuth• Vertical Section

• Quadrant• Polar Coordinate• Rectangular Coordinate• End of Drop• Tangent Section• Measured Depth• Well Inclination• End of Buildup• Horizontal Displacement• Drop Off Rate

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Study Questions

1) Write in the correct terms to correctly complete the following sentence.

Well planning is an important stage prior to the commencement of actual drilling operations toensure that all aspects of the well are tailored to meet the specific _________________________ ofthat well.

2) Which of the following are components of a well plan? Select all the correct answers.

a) Drop Quadrantb) Azimuthc) Quadrantd) Rectangular Coordinatee) End of Wellf) Vertical Sectiong) Polar Coordinate

3) Which of the following are components of a well plan? Select all the correct answers.

a) Hold Angleb) Depth Controlc) Kickoff Pointd) Buildup Ratee) Surface Locationf) Start of Dropg) True Value Downh) Turn Rate

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7 Summary

Directional drilling has become a very important drilling process. It has enabled producers all over theworld to develop subsurface deposits that could never have been reached economically in any othermanner.

In this module, directional drilling was defined along with its historical development.The applications of a directional well as well as the features of a well profile were also covered. Themodule also included information on the types of well profiles and the components of a well plan.

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7 Answers to Study Questions

PART 1No Study Questions

Part 2

1) Which of the following is the correct definition for directional drilling?

a) The science and art of deviating a wellbore along a planned course to a surface target locationthat is a given lateral distance and direction from the horizontal

b) The science and art of deviating a wellbore along a planned course to a subsurface target locationthat has not been Determined

c) The science and art of deviating a wellbore along a planned course to a subsurface target locationthat is a given vertical distance and direction from the horizontal

d) The science and art of deviating a wellbore along a planned course from a surface locationto a target location, both defined with a given coordinate system

2) Which of the following is the most important aspect of controlled directional drilling?

a) It enables producers all over the world to develop subsurface deposits that could never bereached economically in any other manner.

b) It is the science of deviating a wellbore along a planned course to a surface target location that isa given lateral distance and direction from the horizontal.

c) It enables producers all over the world to develop subsurface deposits that could have been lostdue to improper drilling equipment.

d) It enables producers all over the world to kill wild wells.

3) Directional drilling was used initially for remedial operations. Which of the following areexamples of these earlier uses? Select all the correct answers.

a) To drill relief wells to kill blowoutsb) To sidetrack around stuck toolsc) To bring the wellbore back to verticald) For salt dome drillinge) For offshore multiwell drilling

4) Where was the first controlled directional well drilled in 1930?

a) Conroe, Texasb) Huntington Beach, Californiac) Seminole field, Oklahomad) Long Beach, California

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Part 3

5) Exploration wells are drilled for which of the following reasons? Select all the correct answers.

a) To produce an existing fieldb) To determine the extent of a fieldc) To determine whether oil or gas exists in a subsurface rock formationd) To probe the earth where no known hydrocarbons existe) To reach a reservoir that is in excess of 15,000 ft

6) Appraisal wells are drilled for which of the following reasons? Select all the correct answers.

a) To determine the extent of a fieldb) To probe the earth where no known hydrocarbons existc) To produce an existing fieldd) To determine how much area a field coverse) To reach a reservoir that is in excess of 15,000 ft

7) Development wells/Production wells are drilled for which of the following reasons?

a) To probe the earth where no known hydrocarbons existb) To remove hydrocarbons from an existing fieldc) To determine the extent of a fieldd) To reach a reservoir that is in excess of 15,000 ft

8) Match each well with its reason for being drilled.

a) To determine whether oil or gas exists in a subsurface rock formation (1)b) To remove hydrocarbons from an existing field (2)c) To determine the extent or area of coverage of a field (3)

1) Exploration wells2) Development wells/Production wells3) Appraisal wells

Part 4

1) Which of the following are reasons for drilling a directional well? Select all the correct answers

a) To get to trapped oil beneath salt domesb) To get to a target located beneath a city or a sensitive areac) To get past a fishd) To reach a reservoir located below large bodies of watere) To allow for exploration without drilling other complete wells

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2) Which of the following directional drilling applications is the most economical way to developan oil field that is below a large body of water but within drilling reach of land?

a) Offshore multiwell drillingb) Offshore drilling to onshore locationsc) Onshore drilling to offshore locationsd) Multiple exploration wells from a single offshore wellbore

3) Which of the following are applications for drilling a directional well? Select all the correctanswers.

a) Onshore drilling to offshore locationsb) Relief wellsc) Offshore multiwell drillingd) Horizontal wellse) Multiple exploration wells from a single wellbore

4) Which of the following are applications for drilling a directional well? Select all the correctanswers.

a) Sidetrackingb) Salt dome drillingc) Offshore drilling to onshore locationsd) Fault controllinge) Inaccessible locations

5) Which of the following is the best description of a directional drilling application that is usedspecifically to kill a well that is blowing?

a) Salt dome drillingb) Horizontal wellsc) Offshore multiwell drillingd) Relief wells

6) Which of the following is the best description of a directional drilling application that is usedspecifically to intersect a producing formation horizontally to better produce the reservoir?

a) Onshore drilling to offshore locationsb) Offshore multiwell drillingc) Horizontal wellsd) Relief wells

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7) Identify each picture with its directional drilling application.

a) Sidetracking (3)b) Inaccessible location (2)c) Salt dome drilling (1)

8) Identify each picture with its directional drilling application.

a) Onshore drilling to offshore location (3)b) Fault controlling (2)c) Offshore multiwell drilling (1)

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9) Identify each picture with its directional drilling application.

a) Horizontal well (3)b) Multilateral well (2)c) Relief well (1)

10) Identify each picture with its directional drilling application.

a) Extended reach wells (2)b) Fault controlling (1)c) Short radius wells (3)

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11) Extended reach wells are drilled to reach reservoirs that are in excessof _____ meters from the starting point.

a) 500,000b) 5,000c) 500d) 50

12) Which of the following would apply to short radius directional drilling? Select all the correctanswers.

a) Used to isolate higher-/lower-pressured production zones or water sands without settingand cementing a liner

b) Typically reentries of old vertical wellc) Has curves with a 200 to 500 ft radiusd) Has curves with a 143 ft radius or smaller that cannot be drilled with conventional motors

?

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Part 5

11) Write in the correct term to correctly complete the following sentence.

A well profile is the planned well trajectory from the ____surface_________ to the final drillingdepth.

12) Which of the following must be known to determine the best geometric well profile from thesurface to the bottomhole target? Select all the correct answers.

a) The TVD of the targetb) The position of the surface locationc) The position of the target locationd) The density of the target

13) Identify the features of the directional well profile.a) End of Buildup (1)b) Start of Drop (2)c) End of Drop (3)d) Target Displacement (4)e) Well Inclination (5)

14) Match each well profile feature with its definition.

a) The geographical position on earth where the well startsb) The location at a given depth below the surface where the wellbore is deviated in a given

directionc) The change of inclination of a wellbore where the angle is increasedd) Determines the rate a well profile turns in azimuth direction

1) Kickoff Point (b)2) Surface Location (a)3) Buildup Rate (c)4) Turn Rate (d)

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15) Match each well profile feature with its definition.

a) Occurs where the inclination of the borehole is held constantb) The location where the wellbore starts dropping inclinationc) The angle by which the wellbore deviates from the verticald) The change of inclination of a wellbore where the angle is purposely reduced

1) Well Inclination (c)2) Drop Off Rate (d)3) Hold Angle (a)4) Start of Drop (b)

16) Match each well profile feature with its definition.

a) The actual measured vertical depth from a reference point on the surface to a point of interestb) The lateral distance from the surface location to the targetc) Direction of a course measured in a clockwise direction from 0-360o referred to Northd) The length of the projection of the horizontal displacement onto the vertical section plane

defined by its azimuth.

1) True Vertical Depth (a)2) Target Displacement (b)3) Vertical Section (d)4) Azimuth (c)

17) Match each well profile feature with its definition.

a) The actual length of the wellbore from its surface location to any specified stationb) The distance between two points that are projected onto a horizontal planec) A point where a well profile finished dropping inclinationd) The point or location of the oil and gas reservoirs

1) Measured Depth (a)2) Target (d)3) Horizontal Displacement (b)4) End of Drop (c)

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18) Match each well profile feature with its definition.

a) Occurs after a buildup where the inclination of the borehole is held constant for a certain distanceb) The azimuth angle measured from North or South in the direction of East or Westc) A point defined by a distance and a direction relative to Northd) Used to give a target's position in feet or meters with direction of North/South and East/Weste) The location where the wellbore has finished increasing

1) Tangent Section (a)2) Polar Coordinate (c)3) Rectangular Coordinate (d)4) Quadrant (b)5) End of Buildup (e)

19) Which of the following are general types of directional well profiles? Select all the correctanswers.

a) Straightb) Slantc) S-typed) Horizontal

20) This graphic represents which of the followingtypes of directional well profiles.

a) Straight wellb) Horizontal wellc) S-type welld) Slant well

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Part 6

1) Write in the correct terms to correctly complete the following sentence.

Well planning is an important stage prior to the commencement of actual drilling operations toensure that all aspects of the well are tailored to meet the specific ______objectives__________ ofthat well.

2) Which of the following are components of a well plan? Select all the correct answers.

a) Drop Quadrantb) Azimuthc) Quadrantd) Rectangular Coordinatee) End of Wellf) Vertical Sectiong) Polar Coordinate

3) Which of the following are components of a well plan? Select all the correct answers.

a) Hold Angleb) Depth Controlc) Kickoff Pointd) Buildup Ratee) Surface Locationf) Start of Dropg) True Value Downh) Turn Rate

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