UNDERWATER INSPECTION/TESTING/MONITORING OF OFFSHORE STRUCTURES

February 1978

Sponsored by: U.S. DEPARTMENT OF COMMERCE U.S. DEPARTMENT OF ENERGY U.S. DEPARTMENT OF THE INTERIOR

Conducted by: R. Frank Busby Associates 566 s. 23rd Street Arlington, Virginia 22202

Under Department of Commerce Contract No. 7-35336

The opinions expressed in this report are those of the contractor's, and do not necessarily reflect the opinions of the sponsoring activities.

Distributed By NOAA/OFFICE OF OCEAN ENGINEERING

Rockville, MO 20852

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington; D.C. 20402

Stock No. 003--018-00089-0

TABLE OF CONTENTS

PREFACE. i

OVERVIEW 1

1, 0 SUMMARY AND RECOMMENDATIONS. 5

1.1 INSPECTION REQUIREMENTS. 5

1.2 CAPABILITIES - INSPECTION/TESTING. 6

1.3 CAPABILITIES - MONITORING.. 8

1. 4 ON GOING RESEARCH AND DEVELOPMENT PROGRAMS 13

1. 5 RECOMMENDED RESEARCH AND DEVELOPMENT PROGRAMS . 15

2.0 REQUIREMENTS - UNITED STATES 21

2. 1 INSPECTION 21

2.1.1 Federal Government (Legislative) 21

2.1.2 Federal Government (Executive) 22

2.1.2.a Department of the Interior (Geological Survey) 22

2.1.2.b Department of Transportation (Coast Guard) 23

2.1.2.c Department of Transportation (Office of

Pipeline Safety. . . 24

2.1.2.d Department of Labor (OSHA) 25

2.1.2.e Department of Defense (U.S. Navy). 25

2.1.2.f Department of Commerce (National Bureau of

Standards) . . . . 25

2.1.2.f Environmental Protection Agency. 25

2.2 STATE GOVERNMENTS. . . . . . 25

2.3 SOCIETIES/PROFESSIONAL ORGANIZATIONS 26

2.3.1 American Bureau of Shipping. 26

2.3.2 American Petroleum Institute 26

2.4 PLATFORM OPERATORS (U.S. AND FOREIGN). 27

2.5 TRAINING 36

2.6 INSTRUMENTATION STANDARDS. 37

3.0 REQUIREMENTS - NORTH SEA ... 39

ii

PREFACE

The extraction of offshore oil and gas deposits has resulted in installation of massive steel and concrete platforms in progressively deeper and more hostile waters. Concern for the safety of platform personnel, potential damage to the environment, and the assurance of profitable, unimpeded, extraction of these offshore resources is a concern aE host~ountry governments and the offshore operators.

Requirements for underwater inspection of these structures and the techniques and tools to conduct such inspection vary widely from country-to-country. In some instances periodic inspection is required by law; in other instances there is no requirement whatever once the structure has been installed. The instruments to conduct underwater inspections also vary; their effectiveness is sometimes questionable, and the cost of underwater inspection to the operator (which will eventually be borne by the consumer) is high and will get higher as the water depth and complexity of the structure increases.

The purpose of this six month study was: 1) to identify and describe all actual or potential underwater inspection requirements (national and international) for fixed concrete and steel structures promulgated by the governments of offshore oil and gas producing countries and by the offshore operators themselves; 2) to identify and assess the state-of-the-art in underwater non-destructive testing/monitoring/ inspection of offshore structures; 3) to evaluate the capability of servicing and hardware producers to meet the inspection requirements identified; and 4) to describe and establish priorities for specific tasks for technology development that should be undertaken to satisfy current and future requirements. While this study concentrates on fixed offshore oil and gas structures, the results also reflect the state-of-the-art in underwater inspection/testing for other offshore structures as well, e.g., floating power platforms; offshore terminals and deepwater ports.

The data for this study were collected in three stages. First, an intensive literature review was conducted to initially identify those organizations and governments active in projects related to the study goals (the results of this literature survey are presented in Appendix I). Second, telephone interviews were conducted to further identify "Requirements" sources and suppliers/manufacturers of inspection/testing capabilities in the U. S. and Europe. Third, personal interviews were conducted with individuals active in hardware production or inspection services. Personnel and organizations contacted (both by telephone and on a personal basis) are identified in Appendix II (Requirements) and III (Capabilities), respectively. Approximately four months were required to satisfy the data collection phase; the remaining two months were spent analyzing, reducing and synthesizing the data obtained.

i

TABLE OF CONTENTS (CONT.)

3.1 INSPECTION. 39

3.1.1 United Kingdom. 39

3.1.2 Norway. 43

3.1.3 France. 50

3 .1. 4 Ireland 50

3. 1. 5 Denmark 50

3.1.6 Sweden and Belgium. 50

3.1.7 Netherlands 50

3. 1. 8 West Germany. . . . 51

3.2 CLASSIFICATION SOCIETIES. 51

3.2.1 Lloyds Register of Shipping 51

3.2.2 Det Norske Veritas. 53

3.2.3 Bureau Veritas... 55

3.2.4 Gerrnanischer Lloyd. 57

3.3 TRAINING.... 57

3.4 INSTRUMENTATION STANDARDS 58

3.5 REQUIREMENTS - SUMMARY .. 58

4.0-CAPABILITIES-INSPECTION/TESTING 62

4.1 DEPLOYMENT CAPABILITIES .. 63

4.1.1 Ambient Pressure Diving 63

4. 1. 2 SCUBA . . . . . . . . . 65

4.1.3 Surface Supplied/Tended Air or Mixed-Gas Diving 65

4.1.4 Diving Bell ... 65

4.1.5 One Atmosphere Diving Suit (ADS). 67

4.1.6 Manned Submersibles ..... 67

4.1.7 Remotely Controlled Vehicles. 69

4.2 LOCATION/POSITIONING. 72

4.3 CLEANING...... 75

4.4 VISUAL INSPECTION/DOCUMENTATION 77

4.4.1 Human Limitations 77

4.4.2 Data Recording.. 80

4.5 MAGNETIC PARTICLE INSPECTION. 82

4.5.1 The Magnetographic Method 83

4.5.2 Fe Depth Meter. 84

4.6 ULTRASONIC TESTING.. 85

iii

TABLE OF CONTENTS (CONT.)

4.6.l SUIS III. . . 86

4. 6. 2 Wells-Krautkramer DM 1 and USM 2 87

4.6.3 PUNDIT . 87

4.6.4 Acoustic Holography ... 88

4.7 CORROSION POTENTIAL MEASUREMENTS. 92

4.7.1 CP Current Readings 93

4.8 RADIOGRAPHY ..... 94

4.9 INSPECTION/TESTING SUMMARY. 96

5.0 CAPABILITIES - MONITORING .. 98

5.1 ACOUSTIC EMISSION MONITORING. 98

5.2 VIBRATION ANALYSIS MONITORING 100

5.3 MONITORING SUMMARY ... 102

6.0 CAPABILITIES VS REQUIREMENTS. 103

6.1 CONCRETE STRUCTURES 103

6.2 PERSONNEL . 104

6. 3 SPLASH ZONE 105

6.4 LOCATION/POSITIONING. 105

6.5 CLEANING ..... 106

6.6 VISUAL INSPECTION 107

6.7 MAGNETIC PARTICLE INSPECTION. 107

6.8 ULTRASONIC TESTING..... . 108

6.9 CORROSION POTENTIAL MEASUREMENTS. 108

6.10 RADIOGRAPHY . . . 108

6.11 ACOUSTIC EMISSION AND VIBRATION ANALYSIS MONITORING 109

7.0 TECHNOLOGICAL RESEARCH/DEVELOPMENT REQUIREMENTS ... 110

7.1 PERTINENT ON-GOING RESEARCH/DEVELOPMENT PROJECTS. 110

iv

TABLE OF CONTENTS (CONT.}

7.2 SPECIFIC TASKS FOR RESEARCH TECHNOLOGY DEVELOPMENT. ll

7.2.l Immediate Programs. 11

7.2.2 Long-Term Programs. 12

APPENDIX I - REFERENCES CITED . . 12

APPENDIX II - CONGRESSIONAL, STATE, AND FEDERAL AGENCY,

AND EUROPEAN CONTACTS . . . . . . . . . . . . . 12

APPENDIX III - CAPABILITIES - INSPECTION/TESTING/

MONITORING CONTACTS . . . . . . . . . 13

APPENDIX IV - REGULATIONS AND GUIDELINES - U.S. AND FOREIGN (Separate Cover}

APPENDIX V - MANUFACTURES BROCHURES - U.S. AND FOREIGN (Separate Cover )

ADDENDUM . . . . . . . . . . . . . . 135

v

LIST OF TABLES

Table

I PRESENT UNDERWATER NDT TECHNIQUES: ADVANTAGES

AND LIMITATIONS ... 9

II NDT DEPLOYMENT CAPABILITIES: PERFORMANCE AND

V RECOMMENDED TECHNOLOGICAL RESEARCH AND DEVELOPMENT

VI REQUIREMENTS SUMMARY U.S. AND NORTH SEA INSPECTION

VII REQUIREMENTS SUMMARY U.S. AND NORTH SEA INSpECTION/

POTENTIAL. . 12

III MONITORING SYSTEMS SUMMARY PERFORMANCE 14

IV PERTINENT RESEARCH AND DEVELOPMENT PROGRAMS. 16

PROGRAMS . 19

FREQUENCY. . . . . . . . . . . . . . . . . . 59

TESTING RECOMMENDATIONS ....... . 61

VIII U.S./CANADIAN COMPANY'S NDT CAPABILITIES 64

IX WORK INSTRUMENTS - RCV's ...... . 71

x PRESENT AND FUTURE DEEP WATER DRILLING PROJECTS. 73

vi

OVERVIEW

Between 1947 and 1975 over 3,000 structures for the production of oil and gas were erected in the Gulf of Mexico. According to the National Research Council, the offshore regions of the U.S. - of which only about 2 percent have been opened for production - provided 16.4 and 14 percent of the nation's oil and natural gas, respectively. American Petroleum Institute predictions indicate that this yield could double by 1985. Future sites for oil and gas exploration may include the Arctic, Atlantic and Gulf of Alaska, as well as the present Gulf of Mexico and Southern California.

Until 1953 the only requirements for inspection of such structures were those which the platform operator/owner elected to impose upon himself. In the U.S. this situation still prevails although the U.S. Geological Survey in 1953 and the Occupational Safety and Health Administration in 1970 obtained statuatory permission to conduct and/or require inspection