Petroleum Engineering 406 Lesson 2 Well Control

Read Well Control Manual Chapter 4-6 Homework 1 Due Jan. 1/28/04

Causes of Kicks - Tripping Failure to keep the hole full

Causes of Kicks - Tripping Swabbing

Causes of Kicks Lost circulation

Causes of Kicks - Drilling Insufficient density of drilling fluid Drilling into Abnormal pressure

Causes of Kicks - Other Annular flow after cement job Lost control during DST Drilling into adjacent wells Drilling through (shallow) gas zones at excessive rates

Kick Warnings - Drilling Drilling break Increase in flow rate

Kick Warnings - Drilling Pit gain

Kick Warnings - Drilling Decrease in circulating pressure Increase in pump rate Well flows with pumps off

Kick Warnings - Tripping Improper hole fill DO NOT WAIT FOR PIT GAIN OR FOR THE WELL TO FLOW What should you do if the well is not taking the proper fill on a trip?

Shut In Procedures - Drilling Soft Shut In Pick up the kelly until the tool joint clears the floor. Shut down the pumps. Check for flow. If flowing, open the HCR valve. Close BOP. Close choke. Hard Shut In Pick up the kelly until the tool joint clears the floor. Shut down the pumps. Check for flow. If flowing, Close BOP. Open HCR valve. Close choke.

Shut In Procedures - Drilling Soft Shut In Notify supervisors Read & record SIDPP, SICP, Pit Gain, Time, Date Prepare to implement kill. Hard Shut In Notify supervisors Read & record SIDPP, SICP, Pit Gain, Time, Date Prepare to implement kill.

Shut In Procedures - Tripping 1. Set slips below top tool joint 2. Stab a full opening safety valve and close it. 3. Open the HCR and close the BOP, and choke 4. Pick up and stab the kelly or a pump-in line

Shut In Procedures - Tripping 5. Open the safety valve. 6. Notify the supervisors. 7. Read and record SIDPP, SICP, Pit gain, TVD of Well, TVD of bit, time, and date. 8. Prepare to implement kill.

Shut In Procedures - Diverters With diverters in use (prior to setting surface casing) DO NOT SHUT IN WELL - DIVERT.

Shut In Procedures - Casing 1. Lower casing until a swage and valve can be stabbed. 2. Close the casing rams or annular preventer. 3. Stab the swage and valve. 4. Notify supervisor 5. Read and record pressures 6. Prepare to kill well

Well Kill Methods Wait & Weight method Driller’s method Circulate & weight Concurrent method

Well Kill Methods Reverse circulation Dynamic kill Bullheading Lubricate and bleed Volumetric

Constant BHP Well Control

Wait & Weight Method Weight up mud to KWM and complete kill sheet Circulate KWM to bit following decline schedule Circulate KWM back to surface maintaining FCP on drillpipe pressure

Wait & Weight Method 7000

Wait & Weight Method When well is full of KWM, Shut in well Check for remaining pressures If surface pressures are zero, check for flow by cracking choke If no flow, carefully open BOP’s Circulate around again

Wait & Weight - Advantages Kill well in one circulation Least amount of maximum casing pressures

Driller’s Method Shut in well long enough to measured stabilized SI pressures Circulate kick fluids from wellbore with original weight mud maintaining ICP on drillpipe When kick fluids are circulated out, shut in well

Driller’s Method Weight up mud to KWM Circulate KWM to bit following pressure decline schedule Continue circulating KWM around maintaining FCP until KWM reaches surface Shut well in, check for pressures, flow etc.

Driller’s Method

Driller’s Method - Advantages Short shut in times Easy

Circulate & Weight Shut in long enough to measure stabilized SI pressures Begin circulating kick from wellbore with OWM at ICP While circulating, isolate one pit and begin to weight up to KWM When mud is weighted up, switch pump suction to weighted pit, and follow W&W

Circulate & Weight - Advantages Best of W&W and Driller’s

Concurrent method Weight up and circulate in increments Takes one complete circulation for each increment

Reverse Circulation Circulate down annulus and up the drillpipe or tubing. Used extensively in workovers and completions

Dynamic Kill For blowout control For shallow gas Use high pump speeds and viscosities to generate high annular friction pressures Annular friction used instead of surface choke For shallow gas Circulate as fast as rig pumps will allow through diverters DO NOT HOLD ANY BACK PRESSURE

Bullheading Pump kill fluid down wellbore, usually at relatively high speeds to force formation fluids back into formation Used predominantly in: Workover and completion operations Austin Chalk flow drilling When danger of H2S

Lubricate & Bleed Only applicable with gas at the surface Pump in KWM into wellbore Let KWM fall for some time Bleed off gas Repeat

Volumetric Method Used when circulation is not possible or when gas is migrating in closed in well As surface pressures increase due to gas migration, bleed off excessive pressure and allow bubble to expand. Continue until circulation can be resumed or until gas reaches surface

Use of Kill Sheet Pre-recorded information SPP Pump output Drillstring capacity Annular capacity Pressure limitations Circulation times Number of strokes

Use of Kill Sheet Post kick information SIDPP SICP Pit gain Time Date

Use of Kill Sheet Calculate: Plot Pressure Decline Schedule KWM = SIDPP/0.052/TVD + OWM ICP = SPP + SIDPP FCP = SPP*KWM/OWM Plot Pressure Decline Schedule

Kill Sheet

Kill Sheet Plot ICP Plot FCP