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HP/HT well construction, well control HP/HT well construction, well control issues and risk managementissues and risk management

How can a Research Institute contribute ?How can a Research Institute contribute ?

Presented by Rolv Rommetveit, Rogaland Research

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ContentsContents

• Background• R&D highlights within HPHT• The HPHT Laboratory• HPHT Integrated Studies• How can an R&D Institute contribute ?

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HPHT Drilling Research at RFHPHT Drilling Research at RF--Rogaland ResearchRogaland Research

Background

• Prospects and Discoveries in Central Graben

• Serious Well Control Problems during drilling of HPHT

Wells

• Need for understanding dynamic Pressures as well as

Temperature effects in HPHT wells

• HPHT Fields under development require solutions to

production and reservoir related problems as well

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HPHT HPHT Research Activities at RFResearch Activities at RF--Rogaland ResearchRogaland Research

From 1990 R&D within drilling and well technology started at RF

• 1991 - 93“Accurate Pressure Conditions in Deep, Hot Wells”JIP with 5 participantsDevelopment of an Advanced Model for Accurate Pressure andTemperature Calculations

• 1991 - 94Strategic Technology Programme from NFR“Well Technology in Deep, Hot Wells

• Productions Problems related to HPHT reservoirs• Drilling related problems was further studied• Needs for Laboratories to study these phenomena was

defined

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HPHT Drilling Research at RFHPHT Drilling Research at RF--Rogaland ResearchRogaland Research

1990 - 94: “Understanding Pressures and Temperatures during drilling under extreme conditions”(DEA-E-33 project)

Focus on:– Field Measurements of P and T from 2 HPHT Wells– Fluid Properties at HPHT (Rheology and Density)– Verification of Pressure and Temperature models– Development of recommendations for safer Tripping and

Drilling

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HPHT field dataHPHT field data

• Time based surface data• Time based downhole data

– Near BOP– Top and bottom of BHA– 1000 m above BHA

• The data cover detailed tests in cased holes:– Gel tests– Surge and swab– Circulation sweeps– …

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Laboratory experimentsLaboratory experiments

• 10 HPHT mud samples collected and analysed

• Mud density at HPHT• Mud rheology at HPHT• Correlation based models developed

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Case 1:• 2.1 s.g. WBM• Vertical, 5000 m• Gel tests inside 9 5/8”

casingTests at bottom inside 7” liner

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Case 2:• 2.2 s.g. OBM• Deviated, up to 27°• 5100 m MD• Tests inside 9 7/8”

casing

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Bottom hole pressure, WBMBottom hole pressure, WBM

15 20 25 30 35400

500

600

700

800

900

1000

1100

1200

Pre

ssur

e (b

ar)

Time (hours)

Gel

test

s w

. rot

atio

n

Gel

test

s w

.o. r

otat

ion

Rea

min

g ce

men

t

Pre

ssur

e te

st

Dre

ss o

ff ce

men

t plu

g

Circ

. and

con

d. m

ud

Sur

ge a

nd s

wab

Circ

ulat

ion

swee

ps, 2

00-1

000

l/min

Sta

tic p

erio

d

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Pressure, gel test Pressure, gel test w.ow.o. rot., WBM. rot., WBM

18.3 18.4 18.5 18.6 18.7 18.8800

810

820

830

840

850

860

Pre

ssur

e (b

ar)

Time (hours)

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Pressure, swab/surge, WBMPressure, swab/surge, WBM

27.4 27.5 27.6 27.7 27.8950

1000

1050

1100

1150

1200

1250

Pres

sure

(bar

)

Time (hours)

600 l/min No circ.

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Temperature, Transient Temperature, Transient p,Tp,T--model, model, OBMOBM

35 40 45120

125

130

135

140

145

150

155

160

165

Time (hours)

Te

mpe

ratu

re (C

)Measured dataCalculation

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Operational recommendations developed Operational recommendations developed for :for :

• Pressure transmission• Drilling

– Swab in critical zones• Recommended procedure for

critical zones– Surge in critical zones– Gelling

• Mud properties– Rheology and gel strength

are very temperature dependent – HPHT laboratory measurements are recommended

• Use of thermo-hydraulic analysis

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HPHT HPHT Research Activities at RFResearch Activities at RF--Rogaland ResearchRogaland Research

ELF HPHT Drilling and Production Programme

A Major Research Co-operationBased on Elgyn / Franklin needs

1992 - 1995– Drilling Programme– Production Programme– HPHT Laboratory

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Dynamic Barite Sag

in Drilling Fluids

Research funded by Elf and ENI / Norsk Agip

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Dynamic barite sagging:

When weight material in drilling fluid precipitates during circulation.

• All drilling fluids show dynamic sagging during laminar shear flow.

• Large differences in different drilling fluids with respect to rate of dynamic sagging.

Dynamic Barite SagDynamic Barite Sag

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Dynamic Barite SagDynamic Barite Sag

0.00E+00

5.00E-06

1.00E-05

1.50E-05

2.00E-05

2.50E-05

Agip oilbased:

Agip waterbased:

Glydril: VersaVert

80/20:

Nova Plus60/40:

CMC: Xanthan:

Summary of sagging properties of drilling muds

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Dynamic Barite SagDynamic Barite Sag

• A method to measure dynamic sagging in drilling fluids has been developed.

• A formalism to analyse the results have been established

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RF-ROGALAND RESEARCH

HPHT Fluids Laboratory

Testing of fluids at: Pressures up to 1500 bar

Temperatures up to 200º C

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The RF rig areaThe RF rig area

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APPLICATION IN RESERVOIRSAPPLICATION IN RESERVOIRS

• Phase behaviour of fluid mixtures• Retrograde condensate evaluation• Dew point determination• Formation blocking• Emulsion stability• Foam properties

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APPLICATION IN PRODUCTIONAPPLICATION IN PRODUCTION

• Scale formation studies and inhibition• Wax and asphaltene formation• Corrosion evaluation• Chemical stability• Emulsion stability• Supercritical properties of gases• Solvent properties in fluids

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APPLICATIONS IN COMPLETIONAPPLICATIONS IN COMPLETION

• Well control• Completion fluid characterization• Gas / condensate solubility in completion fluids• Thermal properties of packer fluids• Salt solubility in brines• Kill pill stability• Fluid compatibilities• Precipitation in the formation• Emulsion stability

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APPLICATIONS IN DRILLINGAPPLICATIONS IN DRILLING

• Well control• Kick control

– Gas, condensate and oil influx in oil and water based mud

• ECD management• Drilling fluid characterization

– Emulsion stability under HPHT conditions– Rheology stability under HPHT conditions– Static barite sagging under HPHT conditions– Thermophysical properties in fluids

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The HPHT Mud CellPrinciple•Piston cell with piston controlled by hydraulic pressure inside a heating cabinet

•The cell volume (e.g. Position of the piston) is read by a linear encoder mounted on the side

Technical data•Pressure range: 0 to 1.370 bar

•Temperature limit: 200 C

•Volume: 500 ml ( + 0.2% )

•Material: Solid Hastelloy

Technical data•Position encoder for volume measurements

•Robust tubing and valves to allow handling fluids weighted with solid agents

•Well for temperature probe in the cell body

•Computer interfaced data acquisition

Applications•Thermal expansion of fluids

•Compressibility of fluid

•Temperature and pressure effects of fluid components

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HPHT-laboratory PVT-cell•Advanced PVT-apparatus

•Two interconnected variable volume chambers with motor-driven pistons working directly into cells

•Fully computer-interfaced control and data acquisition

•Interchangable end-sections with a variety of sapphire windows for video-monitor or fiber-optic interface detection

•Applications•All standard PVT with unprecedented accuracy

•Direct dewpoint measurement

•Visual (full-view colour video monitor) and quantitative studies of all phase transition phenomena (LV, L1,L2, Solid precipitation,...)

Principle•Similar to two big yolumetric pumps placed vertically within a large thermostat; with the pump cylinders utilized as cells

•Pistons can compress sample or displace it back and forth to display interesting phenomena in windows

Technical data•1.500 bar maximum working pressure (20.000 psi)

•-30 to 230o C temperature range

•Volume: 700 cc (cell1), 100 cc (cell 2)Accuracy: γL-Level

•Material: Solid HastelloyVespel (seals)Al2O3 (windows)

•Minimal dead volumes (valves integrated in cell bodies)

•Flush-mounted pressure transducers

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ConclusionConclusion

• HPHT Fluids laboratory is highly relevant for drilling ,completion and reservoir related studies

• Application in– Drilling and completion fluid characterization– Well control / kick control– Gas / condensate solubility– Baryte sag– Fluid stability– Fluid properties vs. Pressure and Temperature

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HPHT Drilling Research:HPHT Drilling Research:Kick Kick ModellingModelling and Controland Control

• A GENERAL TOOL FOR WELL CONTROL ENGINEERING AND ANALYSIS– A JIP for development of RF Kick Simulator

• Activities related to HPHT well control:– Extended PVT model– Special aspects of kicks in HPHT wells– Surface gas separation and flaring capabilities

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KICKKICK

Design tool forwork station

(DEA-E-5)

Dissolvedgas transport

PVT-experi-ments in OBM

Shallowgas kicks

Multilateralwell control

Special kill procedures Multiple kicks from

multiple zones

Kick with lostcirculation

Kick for slimhole drilling

Gas rise inhighly gelled mud

Full scale kick tests for SHD

(DEA-E-55)Deep waterkick module

General EOS-basedPVT-module

HPHT Conden-sate kicks

Full scale kick experimentsin horizontal wells

(DEA-E-50)

Kick development inhorizontal wells

Verificationv.s. kick tests

Full scale kick tests in OBM

(DEA-E-9)

Gas slipanalysis

Kill of under-ground flow

Blow-outkill model

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Undetected connection kick Undetected connection kick IleIle1m1m33 kick, OBM, circ 1200 l/minkick, OBM, circ 1200 l/min

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Uniqueness of RF KickUniqueness of RF Kick

• Can model gas, condensate and oil kicks (advanced PVT module)

• Well suited for HPHT conditions• Verified for ultra-deep conditions• Can model complex scenarios (with lost circulstion etc.)• Realistic gas transport model enable degasser design

evaluations • Less conservative (more realistic) than other models• Special wellsite version for kick tolerance evaluations on

critical wells available• A necessary tool in the operator’s tool-kit for special wells

and operations

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HPHT R&DThermo-hydraulic modelling (PRESMOD)

HPHT R&DHPHT R&DThermoThermo--hydraulic modelling (PRESMOD)hydraulic modelling (PRESMOD)

• Coupled pressure and temperature simulator

• Radial and axial discretization

• Dynamic simulations for studies of operational effects on pressure and temperature profiles

• State of the art rheology and density models with possibilities to input of fluid lab. data

• JIP on HPHT Hydraulic Modeling since 1990

• Elf Transient WellboreTemperature Model Belzeb

• Results from DEA-E-33 tests improved Model

• Extensive verification • HPHT wells• Extended Reach Wells• Deep Water wells

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Presmod Value and uniquenessPresmod Value and uniqueness

• Presmod is a unique tool to optimize drilling procedures in wells with small margins

• Presmod takes into full account the impact of operations-driven T and P changes on the ECDs

• Casing running can be optimized

• Pressure loss 81/2” section CsFK mud• Kristin well case

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HPHT Research ; HPHT Research ; Critical pressure effectsCritical pressure effects

• Transient surge and swab pressure– Compressibility– Friction– Hole and casing elasticity

• Transient gel breaking pressure– Pump start-up and surge/swab when drilling

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Critical Pressure EffectsCritical Pressure Effects

Transient flow model with gel build-up and

gel breaking

2. Pressure transmissionlaboratory experiments

5. HPHTfield tests

3. Flow start-up lab. experiments

Research activities Computer software

1. Fluid characterization

4. Transient flow modeling

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Gel breaking pressure near bottomGel breaking pressure near bottom

18.74 18.75 18.76 18.77 18.78 18.79 18.8815

820

825

830

835

840

845

Time (hours)

Pressure at gauge A2 (DEA-E-33 WBM)

Pre

ssur

e (b

ar)

Measured dataNo GEL With gelling

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HTHP surge and swab calculationHTHP surge and swab calculation

27.38 27.39 27.4 27.41 27.42 27.431000

1050

1100

1150

1200

1250

1300

1350

Time (hours)

Pressure at gauge A2 (DEA-E-33 WBM)

Pre

ssur

e (b

ar)

Measured data Dynamic calculationSteady state

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KickRisk KickRisk –– project goalsproject goals

Develop a tool that:

• Quantifies uncertainty to kick and blowout

• Reflects risk related to different design alternatives

• Highlights critical factors• Assists identification of risk

reducing measures• Is a basis for cost-benefit

studies of alternate measures

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KickRisk OverviewKickRisk Overview

Kick Analysis

Loss of wellcontrol

CompletedIn useEvaluationFurther development

CompletedQualificationPilot studyFurther development

Blowout flow module

In progress

Norsk AgipOljedirektoratetStatoil (upgrade)

Norsk AgipNorsk Hydro

Norsk AgipNorsk HydroOljedirektoratet

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KickRiskKickRisk Kvitebjørn Kvitebjørn StudyStudy

• Objectives:– Quantify overall kick probabilities– Identify critical factors– Compare OBM and CsKF in terms

of kick probability– Quantify fracturing probabilites– Sensitivity analysis on mudweight

• Methodology:– Data gathering via expert team Interviews– Analysis using KickRisk: Risk Analysis module

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KickRiskKickRisk Kvitebjørn Kvitebjørn StudyStudy

• Analysis of fracturing probabilities for CsKF

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Example of applicationExample of application

KickRisk study on the Kristin field

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HPHT well studies in Rogaland Research HPHT well studies in Rogaland Research GroupGroup

• Numerous HPHT wells drilled in Norway including 2/4-14 & 16

• Pre- and post analysis of well control• BP UK Marnock

• Post analysis of well control problems• BP UK Devonick

• theoretical evaluations• laboratory investigations• computer simulations and scenario

developments with advanced modeling tools; drilling & completions

• implementing learning's in procedures and operations

• training• operational support

• BP Baku Shah Deniz wells• Well control & transient hydraulics

evaluations• Gas diffusion• Operational support

• Kvitebjørn ; Statoil• Computer simulations and scenario

developments; advanced hydraulics• Kick Risk studies

• Kristin ; Statoil• theoretical evaluations; gas diffusion• computer simulations and scenario

developments with advanced modeling tools; drilling & completions

• implementing learning's in procedures and operations

• training• Kick Risk studies

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Topics for a Well Control StudyTopics for a Well Control Study

– Hydraulic calculations (ECD, swab pressures, temperature effects)

– Kick Tolerances (swabbed, drilled and pressured fault kicks)

– Undetected Kicks (in oil based Mud)– Gas Migration (free gas migration in brine) – Gas diffusion– Kill Methods – Surface Flow parameters/ Mud Gas Separator– Comparing kick behavior in brine vs. oil based

Mud.

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Value of advanced computer modelingValue of advanced computer modeling

• Advanced computer models can be very valuable in both the planning and training phase:– Identify specific well control risks– Input to Well Control Procedures (verify vs. improve)– Contribute to optimization of well design– Develop new procedures– Realistic training– Improve knowledge of HPHT wells– Improve kick tolerance calculations

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• Well control and hydraulic studies using advanced , transient modelling tools

• Planning, operation, and training• Development of procedures

• Operational support • QRA analysis

– Kick probability using KickRisk– Operational risks

• Utilize HPHT Laboratory• Drilling, Completion, Production and reservoir studies

• Understand fully fluid properties ( barite-sag, stability, gas diffusion)

Future contribution from RF Group in order to unlock the HPHT Challenge

Future contribution from RF Group in order Future contribution from RF Group in order to unlock the HPHT Challengeto unlock the HPHT Challenge