「Japan's Methane Hydrate R&D Program」

Comprehensive Report ofPhase 2 & 3 Research Results

Research Group for Field Development Technology

Research Group for Field Development Technology

Research Group for Resources Assessment

Environmental Impact Assessment TeamFebruary 2019
Research Consortium for Methane Hydrate Resources in Japan

Cover Pictures:
Top: Second Offshore Production Test in 2017 (Research Group for Field Development Technology)
Bottom Left: Large-scale Apparatus for Evaluation of Sand Production (Research Group for Production Method andModeling）
Bottom Middle: Reservoir Model (Research Group for Resources Assessment)
Bottom Right: Environment Monitoring System (Environmental Impact Assessment Team）

AbstractDuring the Japanese fiscal years (FY) 2009-2018, MH21, the Research Consortium for Methane
Hydrate Resources in Japan lead by Japan Oil, Gas and Metals National Corporation (JOGMEC) andthe National Institute of Advanced Industrial Science and Technology (AIST) carried out Phase 2 andPhase 3 studies of Japan's Methane Hydrate R&D Program that was announced in July 2001 andfunded by the Japanese Ministry of Economy, Trade and Industry (METI).
During the previous Phase 1 period, the concept of a “methane hydrate concentrated zone” that consistsof highly-saturated methane hydrate deposits in sandy turbidite layers was established throughexploration and drilling in the Eastern Nankai Trough. In addition, a possible energy-efficient
depressurization method was proven to be an energy-efficient production technique as a result ofonshore production tests.
During the following phase 2 and 3, the first offshore production test conducted in 2013 in the Eastern
Nankai Trough area was the world’s first attempt to extract gas from marine methane hydrate deposits.
The test was terminated earlier than expected due to sand production, however, it verified the fact thatthe depressurization method can be applicable to offshore wells, and produced 119,000 ㎥ of methanegas during the six-day production period.
After development and implementation of certain advanced technologies aimed at enabling morestable operations, the second offshore production test was carried out in 2017 in the same region.
Twelve days of flow was realized at the first well in spite of intermittent sand issues. In the second
well, with reinforced sand mitigations, the flow period was extended to a total of 24 days despite being
interrupted by rough weather conditions and series flow assurance issues. Total gas volume producedreached 263,000 ㎥.
During the production tests, a significant amount of data about gas and water production rates, solidand fluid samples, and pressure and temperature in the producer and monitoring boreholes wasobtained in addition to geological and petro-physical information obtained from geophysical logging
and pressure core sampling. This data was delivered to facilitate studies into reservoir responses andgas production in the reservoir.
Furthermore, the gas and water production results of the second test showed some discrepancies fromthe model-based predictions, a fact that highlighted that our knowledge and understanding of methanehydrate reservoir characters and physics are not sufficient. The rate of gas obtained also did not meet
economical demand, and as a result of the above, further studies focused on obtaining more accurate
predictions and enhancing production are still necessary.
Along with the field trials, resource assessment of domestic waters progressed, and a number ofpotential methane hydrate concentrated zones were discovered after studying newly available seismic
data. Moreover, studies into the field development system, pressure coring, and core analysistechnologies that were used for domestic and a number of foreign samples and environmental impacts
assessment were carried out.
During the study period, China performed an offshore production test in 2017, and India conducted an
exploratory drilling campaign aimed at realizing offshore production tests with collaboration fromJapan. Furthermore, the United States carried out a field trial of CH4-CO2 exchange with Japan. An
extended-term production test planning and field survey was initiated in Alaska based on Japan-UScollaboration. Other offshore surveys were carried out in many parts of the world. The field of study
has spread from laboratories and computer studies into the real world, and as a result, researchers are
now facing the actual characteristics and complexities of Mother Nature.
This report presents a summary of the progress of the study, resource assessments, information aboutgas production technology, results of production attempts, and other related fundamental andapplication study results.
The study was carried out by MH21 with the collaboration of many domestic and international
corporations, universities, and research institutes, and realized by the cooperation of local Governmentand communities. MH21 members acknowledge this support and collaborative partnerships.

February 2019
Research Consortium for Methane Hydrate Resources in Japan

Comprehensive Report of Phase 2 & 3 Research Results

CONTENTS
Abstract
ⅠIntroduction

ⅡCurrent Situation Regarding Methane Hydrate R&D
1. Some key points about the characteristics of methane hydrate········································ Ⅱ-1
2. Overview of MH21 R & D in Phase 2 and 3, and recent overseas R & D trends ··················· Ⅱ-5

Ⅲ

2.1

Overview of MH21 R & D in Phase 2 and 3 ···················································· Ⅱ-5

2.2

Recent overseas R & D trends ···································································· Ⅱ-6

Resources Evaluation of the Methane Hydrate offshore Japan

1. Methane Hydrate as a possible resource are BSR and MHCZ (concept of methane hydrate
concentrated zone) ························································································ Ⅲ-1
2. Resources Evaluation of the Methane Hydrate Offshore Japan ······································ Ⅲ-42.1

BSR Distribution ················································································ Ⅲ-4

3. Methane Hydrate System Evaluation ··································································· Ⅲ-6············································· Ⅲ-7

3.1

Microbiological Study of Methane Generation

3.2

Methane Hydrate System Evaluation Using Basin Scale Simulator

3.3

Summary and Future Work ······································································ Ⅲ-9······················ Ⅲ-7

4. Summary of Resources Evaluation of Methane Hydrate ············································· Ⅲ-9ⅣGas Production Techniques from Methane Hydrate Reservoir

1. Basic ideas behind gas production and advances in verification ····································· Ⅳ-1

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2. Process of the First and Second Offshore Production Tests ·········································· Ⅳ-7
2.1

Location of the First and Second Offshore Production Tests and Related Geological Conditions…………Ⅳ-72.2

Overview of Offshore Production Tests and Design Concepts of Used Boreholes ········· Ⅳ-102.3Production Test System ··········································································· Ⅳ-182.4

Sand Control Device ·············································································· Ⅳ-222.5

Monitoring system device ······································································· Ⅳ-292.5.1

Downhole monitoring ······································································ Ⅳ-292.5.2

Four component seismic survey ························································· Ⅳ-37

3. Data and information that the first and the second offshore production test for methane hydrate
provided ···································································································· Ⅳ-443.1

Data of Well, Logging, the Core and the Reservoir ·········································· Ⅳ-44

3.1.1

Well Logging and Coring in First and Second Offshore Production Tests ············· Ⅳ-44

3.1.2

Characteristics of MH Reservoir from Well Logging and Core Data ··················· Ⅳ-45

3.1.3

Summary of MH Reservoir ································································ Ⅳ-463.2

Gas/water Production and Gas Production Behaviors Interpreted from Monitoring Data · Ⅳ-50

3.3

Sample Analysis ··················································································· Ⅳ-623.3.1

Summary of Production Gas Analysis ···················································· Ⅳ-623.3.2

Summary of Production Water Analysis ·················································· Ⅳ-62

4. Major Findings from the Two Offshore Production Tests …………………………………… Ⅳ-69
5. Study of Long-term Onshore Gas Hydrate Production Testing ····································· Ⅳ-75

ⅤDevelopment of Fundamental Technology
1. Core Sampling Technology and Results ································································· Ⅴ-1
2. Pressure Coring and Analysis Technology (Pressure-core Nondestructive Analysis Tools PNATs) Ⅴ-5

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2.1

Introduction ························································································· Ⅴ-5

2.2

Pressure-core Nondestructive Analysis Tools (PNATs) ········································ Ⅴ-62.3

Outline of PNAT’s ················································································· Ⅴ-73. Modeling and Numerical Simulation Technology ······················································ Ⅴ-83.1

MH21-HYDRES ··················································································· Ⅴ-83.2

COTHMA ························································································· Ⅴ-153.3

Geomechanics-related Studies ··································································· Ⅴ-20

4. Study of Sand Production ············································································ Ⅴ-39
4.1

Large-scale Apparatus for Evaluation of Sand Production ··································· Ⅴ-39

5. Study of Flow Assurance ················································································· Ⅴ-42
5.1

Visualization Experiment ········································································ Ⅴ-42

5.2

Experiment on Flow-Loop ······································································· Ⅴ-45

6. Development of Technology for Advanced Production Method ····································· Ⅴ-496.1

Stimulation and Rehabilitation of Production Wells ·········································· Ⅴ-49

6.2

Enhanced Gas Recovery Method ································································ Ⅴ-53

7. Metocean Study and Stability of Seabed ······························································· Ⅴ-61

Ⅵ7.1

Metocean Study ··················································································· Ⅴ-61

7.2

Submarine Ground ················································································ Ⅴ-67

Study of Methane Hydrate Production System and Evaluation of Economics andEROI
1. Basic Plans and Issues of MH Production System ················································· Ⅵ-1
2. Evaluation of the Economics and EROI ····························································· Ⅵ-6

Ⅶ

Environmental Studies ·········································································· Ⅶ-1

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VIII

Administrative Operation

1. Budget ································································································ Ⅷ-1
2. Public Relations ····················································································· Ⅷ-1
2.1

Conference Presentations and Publications ··············································· Ⅷ-1

2.2

Reinforcement of internal cooperation and PR ··········································· Ⅷ-3

2.3

Awards ························································································ Ⅷ-4

3. Patents ································································································· Ⅷ-4

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