The SPE Foundation through member donations and a ... · •Well Control Training and Certification Program ... • Products: two simulators, one for blowout events and the other

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Primary funding is provided by

The SPE Foundation through member donations and a contribution from Offshore Europe

The Society is grateful to those companies that allow their professionals to serve as lecturers

Additional support provided by AIME

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Ways to Successfully Reduce WellBlowout Events

Otto Luiz Alcantara Santos

Petróleo Brasileiro S.A. - Petrobras

Society of Petroleum Engineers Distinguished Lecturer Programwww.spe.org/dl

3

Motivation for the Lecture

Before 1988 After 1988

Blowouts in Brazil DuringDrilling Operations

1980 1990 2000 2010Year

1

3

5

0

2

4

6

Num

ber o

f Blo

wou

ts

1

3

5

0

2

4

6

4

To show how a major oil

company can act to preserve its

personnel, assets and image

from the consequences of a

well blowout in drilling and

production operations

Lecture Objective

5

• Introduction

• Well Control Training and CertificationProgram

• Well Control in Drilling and ProductionOperations

• Well Control in Deep and Ultra-Deep Waters

• Research and Development in Well Controlin Ultra-Deep Waters

• Conclusions

Presentation Outline

6

• Kicks – Undesirable flow from the

formation into the well that happens

when the pressure inside the well

becomes less than the pressure of that

formation.

• Blowouts – Uncontrolled flow from the

formation into the well and then to the

atmosphere, sea bottom or other uncased

formations.

Kicks and Blowouts Definitions

7

Blowouts Classification

Surface Blowout Underground Blowout Cratering

8

Examples of Blowouts

9

• Loss of Human Lives

• Loss of Reserves

• Loss of Equipment

•Production Discontinued

• Environmental Aggression

Consequences of a Blowout

10

Human Factors Review for Offshore Blowouts

Source: Aberdeen Drilling School HPHT Manual

11

• Introduction

• Well Control Training and Certification Program

• Well Control in Drilling and Production Operations


• Research and Development in Well Control in Ultra-Deep Waters

• Conclusions


12

• Well control training starts in 1971

• In 1993, the Well Control Certification and Training Program is created and conducted by Petrobras University

• The program is accredited by WellCAP of IADC in July, 1996

Certification and Training Program in Well Control

13

WellCAP Certificates Issued Until 31 December, 2009

5937319714681272TOTAL

27632003494266

COMBINED (SURFACE/

SUBSEA)

31741194 9741006SURFACE

TOTALSUPERVISIONFUNDAMENTALINTRODUCTORYLEVEL

14

Trained/Certified People

1980 1990 2000 2010Year

100

300

500

0

200

400

600

Num

ber

of C

ertif

ied/

Tra

ined

Peo

ple

100

300

500

0

200

400

600

15

Cumulative Blowouts in Brazil per 1000 Drilled Wells

Blowouts in Brazil per 1000 Drilled Wells X Traine d/Certified People

0

100

200

300

400

500

600

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

Year

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

Tra

ined

/Cer

tifie

d P

eopl

e

Blo

wou

ts p

er 1

000

Dril

led

Wel

ls

Cumulative Blowouts/1000 Drilled Wells

Trained/Certified People

16

• Introduction





• Conclusions


17

• Rig inspections upon receiving it

• Monitoring of well control equipment and kick detection tests

Well Control in Drilling and Production Operations

Personnel (Well Control Team)

Well Control Equipment (Well Control Team)

• Monitoring of well control certificates• Drills at the rig site

18

Well Control in Drilling and Production Operations

Development of Well Safety Standards

• Creation of a committee to review, elaborate and approve internal well safety standards

• There are 17 standards approved and in use

Operations (Well Control Team)

• Elaboration and approval of operational procedures especially in deep waters

• Reinforcement of the use of these operational well safety procedures and standards

19

• Introduction





• Conclusions


20

• Low fracture gradients

• Excessive frictional pressure inside the choke line

• Low temperatures

• Hydrate formation

• Gas in riser

Peculiarities of deepwater and ultra-deepwater well control

21

Subsea Configuration

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• Fracture pressures in deep waters are lower than those found onshore or in shallow waters

• The overburden pressure is lower due the seawater

• Narrow operational window for the mud weight

Low Fracture Gradients

23

Low Fracture Pressure

11,61580289012

10,01580194011

14,11940463010

10,8194026709

10,8177026508

10,8138024707

104138017406

9,8153026005

11,0158044004

10,4158029003

9,3158021002

11,4159023901

Fracture Pressure (lb/gal)

Water Dept (m)

Shoe Depth (m)

Well

24

Pore Pressure

Fracture Pressure

SeaFloor

Shallow Water

Deep Water

....Sea Level

Narrow Operational Window

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• The frictional pressure losses inside the choke line can be excessive during a kick circulation

• Small inside diameter of the choke line and its long length

• The problem is aggravated by the low seawater temperature

Excessive Frictional Pressure Losses Inside the Choke Line

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• High pressure and low temperature at the wellhead are favorable for hydrate formation

• Hydrate can plug the kill and choke lines, the annulus space and the BOP cavities.

• Hydrate formation can be prevented using inhibitors such as salt and glycol.

Hydrate Formation

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• In ultra-deep waters, there are chances of the gas has passed through the BOP and into the riser before well closure

• The use of synthetic oil based mud increases these chances

Gas Inside the Riser After BOP Closure

28

• Introduction





• Conclusions


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• A strategic in-house corporate research program dedicated to ultra-deepwater exploitation systems has been created

• Important research projects portfolio in well safety:

Drilling Hydraulics and Gas MigrationGas Solubility in Synthetic Oil Based Mud Kick Simulator for Field Application Study of Ultra-Deepwater Blowouts

Research and Development

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• Objective: to obtain downhole pressures and temperatures during simulated drilling operations

• Issues Addressed: riser hydraulics and temperatures; critical pressure effects (surge and swab); and gas migration

• Results: comparison of gathered data with computer models

Drilling Hydraulicsand Gas Migration

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• Research conducted through a JIP coordinated by RF - Rogaland Research that used a drillship Campos Basin (Brazil) in a water depth of 2714 m

• The drilling string was equipped with six sensors for recording pressures and temperatures

• Gas migration experiments were done through nitrogen injection with the bit just above the BOP


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Bit @ 4370 m

Sensor # 1 - 1 acquisition/s - 4368 m


4 DC Stands

1 DC Stand

Bit Sub+X-over

2 DP Stands (19.5) Sensor # 3 - 1 acquisition/s - 4166 m


Sensor # 5 - 1 acquisition/3s - 2596 m


1 DP Stand (19.5)

54 DP Stands (19.5)

3 DP Stands (19.5)

28 DP Stands (25.6)

Bit @ 4370 m



4 DC Stands

1 DC Stand

Bit Sub+X-over

2 DP Stands (19.5) Sensor # 3 - 1 acquisition/s - 4166 m




1 DP Stand (19.5)

54 DP Stands (19.5)

3 DP Stands (19.5)

28 DP Stands (25.6)


33


0 72 144 216 288 360 432 504 576 648 7206900

6950

7000

7050

7100

7150

7200

7250

7300

7350

Time (s)

Pre

ssur

e (p

si)

Measuered valuesFilteredSimulated

Measured ValuesFilteredSimulation

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• Objective: to understand the interaction between a gas kick and a synthetic oil based mud

• Issues Addressed: experimental determination and modeling of thermodynamic properties

• Results: experimental data of gas solubility (methane), density and formation volume factor for n-paraffin, ester, emulsions and drilling fluids

Gas Solubility in Synthetic Oil Based Mud

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• Research conducted at UNICAMP (Campinas State University) in a PVT cell with an operating capacity of 177 ºC and 10000 psi

• The current experiments aim at expanding the ranges of pressure and temperature using a new PVT cell with an operating capacity of 200 ºC and 15000 psi

Gas Solubility in Synthetic Oil Based Mud

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The New PVT Cell

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0

40

80

120

160

200

0 10 20 30 40

Pressure [MPa]

Rs

[m³s

td/m

³]

63% NP no additives

78% NP no additives

63% NP with additives


Gas Solubility in the Unweighted Drilling Fluid at 70ºC

10 MPa => 1450 psi

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0.65

0.75

0.85

0.95

0 10 20 30 40Pressure [MPa]

ρρ ρρ[g

/cm

³]

63% NP no additives

78% NP no additives



Density of the UnweightedDrilling Fluid at 70ºC

10 MPa => 1450 psi

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• Objective: to develop a software to assist the drilling engineer in well control issues on an ultra-deepwater drilling rig

• Issues Addressed: estimation of pressure behavior inside an ultra-deepwater well during a gas kick circulation and calculation of kill sheets

• Result: a software to be used by the drilling personnel at rig site

Development of a Kick Simulator

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Kick Simulator Output

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• Objective: to study ultra-deepwater blowouts and their control through the dynamic kill method using relief wells

• Issues Addressed: pressure behavior and gas flow rate during blowouts and the application of the dynamic kill method

• Products: two simulators, one for blowout events and the other for dynamic kill method

Study of Ultra-deepwater Blowouts

42

Subsea Blowout

43

Bot

tonh

ole

Pre

ssur

e (p

si)

Time (s)0 400 800 1200 1600 2000 2400

T I ME (s)

5000

6000

7000

8000

9000

PRES

SÃO

NO

F UND

DOPO

Ç O( p

s i)

200 md

400 md

600 md

BO

TT

OM

HO

LE P

RE

SS

UR

E

(psi

)

Subsea Blowout

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0 400 800 1200 1600TIME (s)

0

50

100

150

200

250

VAZÃ

Ode

GÁS

(mm

scf /

dia )

1000 gpm

1500 gpm2000 gpm

GA

S F

LOW

RA

TE

(m

msc

f/day

)

Dynamic Kill froma Relief Well

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• Effective preventive actions make onshore and

offshore drilling and production operations safer

• Training, well control equipment tests and

elaboration of safety standards are some of these

actions that were responsible for the decrease of

the number of blowouts in Brazil

• Research projects enhanced the understanding of

the well safety processes

Conclusions

46

Questions?

47

Society of Petroleum Engineers Distinguished Lecturer Programwww.spe.org/dl

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Documents

The SPE Foundation through member donations and a ... · •Well Control Training and Certification Program ... • Products: two simulators, one for blowout events and the other