15 operations procedures

PE Skill Group 10

BASIC WELL COMPLETION

May 2003

Operations ProceduresOperations Procedures

PE Skill Group 10


May 2003

ContentContent Operations ProceduresOperations Procedures

• Gravel Packing• Installing Completion String• Other Stimulation/

Completion Requirements• Kicking -off Well and Cleanup

Flow• Post Completion

- Well Surveillance

• Objectives of Well Completion Operations

• Phases of Well Completion Operations

• Pre-Completion- Drilling, Running Casing/

Liners and Cementing• Well Cleaning• Perforation

PE Skill Group 10


May 2003

Objectives of Well Completion OperationsObjectives of Well Completion Operations


What is a successful well completion operations ???

• To complete a well that meet reservoir, production, production technology, surveillance, safety and cost requirements

• Reservoir : Maximise recovery from the field or target sands• Production : Maximize long term production rates (P.I.)• Production Technology : Zero formation damage, control sand

production, completion integrity (i.e. mechanical, corrosion, pressure, downhole conditions), high P.I., meet AOF

• Surveillance : Meet welltest, PLT, pressure / temperature survey, sampling, zone selectivity, etc. needs as required

• Safety : Safe operations and safe well (now and future)• Cost : Within planned cost

A successful well completion operation meets these objectives asrequired

PE Skill Group 10


May 2003

Phases of Well Completion OperationsPhases of Well Completion Operations


Well completion operations start from the time the hydrocarbonzone of interest is drilled to the period of initial production todetermine if completion objectives are met• Pre-Completion

- Drilling, Running Casing / Liners and Cementing - Retrieving old completion

• Well Cleaning• Perforation• Gravel Packing• Installing Completion String• Other Stimulation / Requirements• Kicking-off Well and Cleanup Flow• Post Completion

- Well Surveillance

PE Skill Group 10


May 2003

Pre-Completion - Drilling, Running Casing / Liners, Pre-Completion - Drilling, Running Casing / Liners, Cementing and Pulling Old CompletionCementing and Pulling Old Completion


The objective during is to minimise or prevent formation damagefrom any activities affecting the formation by :

• minimum overbalance• compatible drilling fluids• minimum damaging solids in drilling fluids• for openhole completion

- drill-in fluids to prevent losses- breaker solution to clean mud-cake after setting pre-drilled/

slotted liners • keep hole in size to minimise cement sheath to be perforated• minimise losses into the formation • to kill well for re-completion, use clean fluid

PE Skill Group 10


May 2003

Well CleaningWell Cleaning


Objective is to have clean completion fluid in the well prior toperforation and running completion :

• Clean all surface fluid system (tank, pipings, return lines, etc.) and work string prior to commencing well clean up

• After cementing, RIH with bit and scrapper to clean out casing, clean well and displace well to completion fluids

• Circulate two well volume while scrapping and drilling to remove any cement scale or cuttings until well is clean

PE Skill Group 10


May 2003

Well Cleaning (cont..)Well Cleaning (cont..)


• Displace mud out of the well and replace with seawater by pumping cocktail of :- 50 bbl base oil (if oil based mud used)- 20 - 50 bbl hi-vis (Guar gum or HEC) spacer- 100 - 150 bbl wash pill (Super Pickle 3 % w/v)- 100 - 150 bbl flocculant pill (Dirt Magnet 3 % w/v)- 20 - 50 bbl hi-vis spacer (Guar gum or HEC) spacer- sea water

• Circulate and dump after base oil is returned• Continue circulating at highest possible rates while dumping

returns sea water until NTU reading of 30 to 40• Repeat cocktail if required (i.e. if returns is still dirty)• After seawater returns are cleaned, displace well to completion

brine. Monitor returns to ensure brine is cleaned and weight as required.

PE Skill Group 10


May 2003

PerforationPerforation


Objective is to perforate safely and maximise productivity

Procedures depend on the type of perforating methods :Retrievable Tubing Conveyed Perforation• Run guns on pipe. Set underbalance from cushion• Correlate depth with GR. Set retrievable packer.• Fire gun (drop bar, internal or annulus pressure)• Flow well until cushion or oil to surface• Kill well and POOHWireline Conveyed Perforation (Casing Guns)• RIH casing guns in wireline• Correlate depth with CCL• Fire gun with current from surface• Observe well. POOH

PE Skill Group 10


May 2003

Gravel PackingGravel Packing


• After well in cleaned, perforate zone with RTCP underbalance• Set sump packer on wireline• RIH gravel pack assembly (screen, top packer and gravel pack

tool) on drill pipes• Sting in bottom packer and set top packer• Establish 4 position (squeeze, lower circulation, upper

circulation and reverse) with gravel pack tool• Establish injectivity• Perform acid job if required• With tool in lower circulating position, circulate down gravel

slurry until screen out• Reverse out excess gravel from the work string• Recheck screen out• Perform acid wash as required• POOH

PE Skill Group 10


May 2003

Installing Completion StringInstalling Completion String


• Make up completion string as per planned design• Pressure test each completion accessory and completion

string as required• Make-up and test SCSSSV and control line• Sting into permanent packer (if used) and space-out string• Make up tubing hanger and land string• In multilateral well GR correlation run may be required for

dual completion• Set hydraulic packer

PE Skill Group 10


May 2003

Installing Completion String (cont..)Installing Completion String (cont..)


• Running pre-packed screen• Horizontal sand control

- screens- gravel pack

• Running Electrical Submersible Pump (ESP)• Multilateral completion• Openhole completion• Openhole gravel pack• Running cement evaluation tools - normally after well

cleaning

PE Skill Group 10


May 2003

Other Stimulation / Completion RequirementsOther Stimulation / Completion Requirements


Detailed procedures must be work out with the servicecompanies for any work to be carried out e.g. :

• Hydraulic Fracturing• Resin sand consolidation• Acidisation• Through Tubing Perforation• Integrated Tubing Conveyed Perforation (ITCP)

PE Skill Group 10


May 2003

Other Stimulation / Completion Requirements Other Stimulation / Completion Requirements (cont..)(cont..)


• Running pre-packed screen• Horizontal sand control

- screens- gravel pack

• Running Electrical Submersible Pump (ESP)• Multilateral completion• Openhole completion• Openhole gravel pack• Running cement evaluation tools - normally after

well cleaning

PE Skill Group 10


May 2003

Kicking-off Well and Cleanup FlowKicking-off Well and Cleanup Flow


• Well can be kickoff by either :- Displacing the tubing string to a lighter fluids e.g.

diesel or fresh water- Artificial lift e.g. gas lift

• Flow should be initiated at a low drawdown (i.e. low choke for natural flowing well) to prevent fines movement which can create wellbore damage and possible gas / water coning

• Choke up well gradually• Cleanup flow is the flow period during which completion

fluids, mud filtrate, gel and other "external" fluids are flowed out of the formation and well

PE Skill Group 10


May 2003

Kicking-off Well and Cleanup Flow (cont..)Kicking-off Well and Cleanup Flow (cont..)


• Cleanup flow can take a few hours to one month or longer depending on the well productivity, amount of fluid lost and volume below packer

• True well performance in not known until well is cleaned up• Where practical well should be put under test during

cleanup with all parameters (FWHP, BSW, rates, GOR, etc.) measured

• All completed zones to be cleanup as early as possible as "external" fluids in contact with the formation may create damage over time

PE Skill Group 10


May 2003

Well SurveillanceWell Surveillance


• Keep well under close surveillance during cleanup flow and initial production to determine if objectives are met

• All surface parameters (FWHP, FWHT, BSW, density) to be monitored closely if well cannot be out on test at all time

• Perform IPR / VFP analysis using the latest data to determine productivity

• Carry out bottom hole pressure surveys (reservoir and flowing) as soon as possible after well is cleaned-up

• Perform PBU survey to determine skin if production is below expectation

15 operations procedures

Documents