INSTRUCTOR © 2017, John R. Fanchi All rights reserved. No part of this manual may be reproduced in any form without the express written permission of the author. © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.

To the Instructor The set of files here are designed to help you prepare lectures for your own course using the text Introduction to Petroleum Engineering, J.R. Fanchi and R.L. Christiansen (Wiley, 2017) File format is kept simple so that you can customize the files with relative ease using your own style. You will need to supplement the files to complete the presentation topics.

ROTARY DRILLING © 2017, John R. Fanchi All rights reserved. No part of this manual may be reproduced in any form without the express written permission of the author. © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.

Outline Prime Movers Hoisting System Drill String and Bits Circulating System Well Control System Typical Drilling Problems Pressure Control

PRIME MOVERS © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.

Rotary Drilling System Prime Movers Hoisting System Rotating System Circulating System Controlling System

Purpose of Prime Mover Prime Movers supply rig power Mechanical Rigs Engines directly hooked up to drawworks, rotary table, pumps, etc. Normal maintenance & crews

Prime Movers Engines Provide Power

HOISTING SYSTEM © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.

Hoisting System Derrick or Mast Drawworks Crown Block Traveling Block Hook Hoisting Line Drill Floor Derrick or Mast Drawworks Crown Block & Traveling Block Hook & Swivel Drilling Line (cable) Top Drive (newer technology)

Hoisting System

Finger board under monkey board Derrick or Mast Crown Block Monkey Board Traveling Block Monkey Board Finger board under monkey board Mud Hose Traveling Block

Derrick or Mast V-door Pipe ramp Derrick is raised in sections Mast is raised as single unit

Traveling Block Hook Swivel Kelly

Kelly Kelly Bushing Rotary Table Drill Pipe Swivel

DRILL STRING AND BITS © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.

Drill Pipe Drill Collar Joint Joint Bit Drawworks Crown Block Traveling Block Hook Kelly Rotary Table Drill Floor Drillstring Drill Collar Drill Pipe Swivel Box connection Pin connection Joint Joint

Insert Tricone Drill Bit Pin connection Mud Nozzle or Jet Leg Cone with buttons

Bit Efficiency: Based Upon Cost Per Foot Drilled cost/ft drilled decreases as # of ft drilled increases $/Ft Bit wearing out Time to replace bit Time to drill Bit Efficiency is a measure of when a bit begins to wear out

Weight on Bit Measure WOB using sensors on drill bit bottom hole assembly (BHA) such as MWD Limit WOB so bit is not crushed Bits can withstand approximately 3,000 to 10,000 psi per inch of bit diameter Typical bit diameters are 3 ¾” to 26” Many modern drillstrings include downhole motor in BHA Downhole motor provides more power to bit

Stability Map of Typical PDC Bit Dynamic dysfunction zones Design WOB and RPM to stay in Stable Zone Source: SPE 146561 (2011, Fig. 1)

Torsional Stress Torsion caused by twisting moment (aka torque) Shear or Torsional Stress τ = Tr/J Differential Angle of Twist dϕ/dz = T/GJ ϕ = angle of twist z = length along axis of pipe T = torque J = polar moment of inertia G = shear modulus τ = shear stress T = torque r = outer radius of pipe J = polar moment of inertia

CIRCULATING SYSTEM © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.

Circulating System

Mud System Has Many Purposes Lift cuttings to surface Control formation pressure Protect formations Prevents subsurface fluids (water, gas, oil) from flowing into well Lubricate Cool bit

Drilling Mud Fresh Water – water-based drilling mud Diesel Oil – oil-based drilling mud Synthetic Oil – synthetic-based drilling mud Additives Clay – bentonite Chemicals

Drilling Mud Density Component Density Water 8.3 lbs/gal Bentonite Mud (1 g/cc or 62.4 lb/cu ft) Bentonite Mud 9 to 10 lbs/gal Heavy Mud 15 to 20 lbs/gal

Drilling Mud Is More Dense than Water Component Density Water 8.3 lbs/gal (1 g/cc or 62.4 lb/cu ft) Bentonite Mud 9 to 10 lbs/gal Heavy Mud 15 to 20 lbs/gal

Mud Types – 1 Water based Oil based Foam Mist Air Polymer

Circulating System

Wellbore Failures Related to Mud Weight Optimum MW MW = mud weight PP = pore pressure SFG = shear failure gradient FG = fracture gradient After Zhang, et al, SPE 114273 (2008)

Preventing Formation Damage Drill with: Underbalance pressure Brine Oil-based drilling mud Air

Sluffing (or sloughing) Can occur when mud pressure is inadequate Heaving: Partial or complete collapse of the walls of a hole Cave-in: collapse of the walls of the wellbore

WELL CONTROL SYSTEM © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.

BOP BOP Annular BOP Blind Shear Ram Pipe Ram Kill Line Casing head

TYPICAL DRILLING PROBLEMS

Examples of Drilling Problems Crooked hole Hole sloughing – cave in Stuck pipe Fishing

Sloughing (aka sluffing) Heaving: Partial or complete collapse of the walls of a hole Cave-in: collapse of the walls of the wellbore Source: http://oilgasglossary.com/

Occurs when compressive load > critical value Buckling Tubular deformation Occurs when compressive load > critical value Sinusoidal buckling Tube snaps into sinusoidal shape aka snaking or lateral buckling Helical buckling Tube snaps into helical (spiral) shape

Fishing (aka Retrieving) Fishing Tools

PRESSURE CONTROL

Possible Issues Abnormal Pressure Kick Formation Damage e.g. overpressured formation Kick high pressure formation fluids flowing into wellbore HTHP – high temperature & high pressure Typically >300° F & 10,000 psi Formation Damage Poor rig & crew performance Slow drilling Logistics

Source: http://oilgasglossary.com/ BLOWOUTS Uncontrolled flow of reservoir fluids into wellbore sometimes to surface Source: http://oilgasglossary.com/

Relief Well Dual Strategy Relief Well Event Occurs (e.g. blowout) Kill Well Surface Intervention

Lose drilling mud, e.g. in high perm formation Lost Circulation Lose drilling mud, e.g. in high perm formation

Lost Circulation Lake Peigneur, Louisiana Diagram showing the oil rig disaster is available at http://home.versatel.nl/the_sims/rig/lakepeigneur.htm The rig was drilling in a lake above a salt dome.

Video Lake Peigneur, LA (Nov. 20, 1980) Operations at Lake Peigneur Texaco drilling from surface of lake with 14” drill bit Diamond Crystal Salt Company mining salt under lake Jefferson Island salt mine Major operational problem: flood mine Rig was drilling in a lake above a salt dome.  Video of the oil rig disaster in Lake Peigneur, Louisiana: http://www.youtube.com/watch?v=ddlrGkeOzsI

Lake Peigneur Settlement Texaco and Wilson Brothers paid $44.8 million in settlement $32 million to Diamond Crystal $12.8 million to nearby Live Oak Gardens (residential)

QUESTIONS? © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.

SUPPLEMENT © 2004 John R. Fanchi All rights reserved. Do not copy or distribute.