AN OVERVIEW OF RESEARCH AND POTENTIAL IN VIETNAM

Transcription

1 AN OVERVIEW OF RESEARCH AND INVESTIGATION OF GAS HYDRATE POTENTIAL IN VIETNAM Vu Truong Son 1, Do Tu Chung 1, Trinh Nguyen Tinh 1, Nguyen Bieu 2, Tran Van Tri 2, Nguyen Duc Thang 2, Tran Nghi 3 1. Marine Geology and Mineral Resources Center, 2. Vietnam Union of Geological Sciences, 3. Hanoi University of Science

2 GENERAL INFORMATION In the world, reserve of the gas hydrate (GH) (i.e. methane hydrate, clathrate hydrate) is three times more than the reserve of fossil resources. Reserve of GH as trillions m 3 (after Milkov, A.V 2004). 10% of the estimated t reserve of GH, if exploited, can accommodate the need for natural gas of the entire world in years (JOGMEC ) Therefore, gas hydrate (GH) is considered as the potential energy in the future

3 GENERAL INFORMATION The world s energy demands are becoming more urgent in the rapidly growing global economy Word Energy Outlook (WEO 2010): upto 2035, energy demand of the world will be raise 36%. Traditional energy sources (e.g. coal, peat, petroleum) are increasingly exhausted The World need a new clean energy resources for development

4 Coastal countries and state islands such as United States, Canada, Germany, Russia, India, China, South Korea, Japan, Mexico, etc. pay special attention to research and investigation of GH potential as well as technology in exploration, production and recovery of GH Studies in GH has been carried out since 70s but in small scale Since 1990s: 92 countries, incl. Canada, US, Russia, Germany, Japan, South Korea, China, have invested more in studying GH. Different methods and technology are used in GH researches in each country. General linformation

5 GAS HYDRATE POTENTIAL IN VIETNAM Vietnam s seas is located in Bien Dong sea, where GH potential ranked fifth in Asia by the United States Geological Survey (USGS) GH and BSR have been found in the area near Bien Dong sea Thus, Vietnam is very interested in research and investigation GH potential in marine areas of Vietnam.

6 GAS HYDRATE POTENTIAL IN VIETNAM Although h the understanding di of GH has been known in Vietnam since the 1980s, but Vietnam has not invested yet in research and investigation of potential of this resources. The results of a number of completed studies, investigations and surveys on geology, structure t - tectonic, geomorphology, seabed depth as well as results of the exploration of oil and gas have revealed significant GH potential in Vietnam's seas

7 SITUATION OF RESEARCH AND INVESTIGATION OF GAS HYDRATE POTENTIAL IN VIETNAM The first scientific contributions were of the Russia scientists in V.I. Il'ichev Pacific Oceanological Institute, Far-Eastern Branch of Russian Academy of Sciences. During , scientific research vessels such as the Lavrentiev, A. Nhesmeianov, A. Vinogradov, Gagarinski, the "Kallisto", Volcanolog, Godenko, Socalxiki, Bogorov have conducted the geological, geophysical, geochemical surveys and marine dynamic on the Bien Dong sea and adjacent areas. From these results, maps of geophysical fields (magnetic, gravity, seismic...), geochemistry, geochemical anomalous of gas and petroleum basins (Red River Delta, Tu Chinh - Vung May) have been established. In addition, indications of GH have also been noted in the Vietnam seas. Apart from the USSR scientists (former), there were other research projects of the United States and other countries such as England, Germany, China, Indonesia, Malaysia and France, etc.

8 SITUATION (2) Based on the above obtained research results, the marine databases and an atlat with more than 70 different maps, for example marine geology - geophysics, marine ecosystems and environment, marine hydrotherm - hydrodynamic. The maps of geology, Quaternary - Tertiary sediments, structure - tectonics, geomorphology, seabed depth, oil basins of the Bien Dong sea and adjacent areas at scale of 1/ can be used to forecast potential ti of GH in the Vietnam s seas. Since the 1970s, the prospecting and exploring of oil and gas in the basins: Mekong, Song Hong, Phu Khanh, h Tu Chinhh - Vung May, Nam Con Son, Malay - Tho Chu and offshore islands has been conducted intensively. Collection of 2D seismic profile has been conducted over a total distance of 400,000 km to survey the geological structure beneath the seabed surface, including marine waters at the depth to thousands of meters, and some profiles were crossing the continental slopes.

9 SITUATION (3) The above document is important to establish the geological structure for processing and interpretation of geophysical indicators related to GH. Parallel to the seismic survey, the gas geochemical mapping for prospecting and exploration of oil and gas resources conducted is also important to study and assess potential of GH in Vietnam s seas. Research and investigation of GH potential in Vietnam seas is a new task, so Vietnam lacks an information of technology, human resources as well as equipped facilities for conducting this task. Recently, the mission of research and investigation of GH has been assigned for two key agencies: Vietnam Administration of Seas and Islands (VASI) and Vietnam Oil and Gas Group (PVN). One of the priorities of the above mission is building capacity cpcyfor the research, investigation and exploration of gas hydrate resources.

10 Conditions and prerequisites of gas hydrate formation Geothermal gradient The recorded data of sea water temperature in the Bien Dong sea showed that seabed temperature is a dependant function of the depth (sea temperature varies from Catthe seabed depth of meters depth, and C at meters depth). At the deeper depth in the sea, temperatures decrease down to below 2 0 C. Geothermal gradient is not homogenous across the Sea with the tendency of gradual increasingi with depth of the seabed. In continental shelf, geothermal gradient is of low value (30 o C - 40 o C/km). In continental slope area, the geothermal gradient has high value, from 60 o C- 94 o C/km. Thus, the marine waters of over 350 meter depth in Vietnam sea meets the temperature conditions for the formation of GH.

11 Conditions and prerequisites (2) Water depth and seabed topography p Most of area of the sea has depth of meters. Structures of the seabed topography are mostly in NE - SW and sublatitude orientations, coinciding with the orientation of the Bien Dong sea rift. Volcanoes also present in this areas. The topographical types in this region facilitate the formation of submarine plateaus, uplifting zones, turbidites, mud diapirs, accretionary wedges. In continental slope of the Central and Southeast, seabed topography changes dramatically from a few hundred meters down to meters, making quite steep cliffs. There appear several young volcanoes. This terrain is favorable for the formation of turbidite structure and seabed sedimentary cones.

12 Conditions and prerequisites (3) Tectonic structure The Sea is a marginal sea which has been formed and evolved in many different stages in the Cenozoic period. Vietnam continental slopes are characterized mainly by a passive continental margin in which suitable structures for GH formation include submarine plateaus, uplifting zones, seabed sedimentary cones, turbidites, mud diapirs and mud volcanoes. Particularly in the southern part of the Spratly Islands, there exist accretionary wedges - a very favorable structural type for existence of GH.

13 Conditions and prerequisites (4) In the area of Paracel Islands, system of faults developed extensively, including faults in NE - SW, N - S, NW - SE orientations. In Spratly Islands, fault system developed extensively in different orientations such as NE - SW, sublongitude, sublatitude and NW - SE. In the west continental slope, including the western part of the Paracel Islands, Phu Khanh basin, Nam Con Son basin, Tu Chinh - Vung May basin, the fault system in N S direction develops expensively, as the greatest system in the area. These above faults are the structural factors that are favorable for gases from the deeper part to the upper part to build up the GH. Along the continental slope in western part of the Sea, there occur quite developed young volcanics, including some young mud volcanic. The mud volcanos is one of the supply of gas to form GH. Legend Deep fault Shallow fault Vocalno/magetics Boundary of ocean and continetal crust

14 Conditions and prerequisites (5) Sediments and sources of gases On most of the continental shelf surrounded the Sea continent slopes, Cenozoic basins are formed with a great thickness of organic matter rich Cenozoic sediments, i.e. Red River basin in the north; Phu Khanh basin, Mekong basin and Nam Con Son basin in the west; and Zenmun basin, Spratly Islands basin group in the south. Most of the basin on the continental shelf is the petroleum basin with great potential. Large petroleum basins rich in organic compounds and dissected by younger fault system, are one of the prerequisites to facilitate formation of gas hydrates. 1. Red River basin 2. Paracel basin 3. Phu Khanh basin 4. Mekong basin 5. Nam Con Son basin 6. Zenmun basin 7. Spratly Islands basin

15 Conditions and prerequisites (6) Bottom Simulating Reflector (BSR) GH layer manifests quite clearly on the seismic profiles by bottom simulating reflector and blank zone right on the boundary surface. In a number of works published by Chinese authors, several seismic profiles with BSR related to GH in the north of the Sea, Taiwan basin, Palawan basin, etc. have been mentioned. So far, Vietnam has not any seismic project to determine the BSR for GH research in the Sea. However, we can see BSR on some seismic profiles of oil and gas sections at the continental slope region of Vietnam. Seismic profile in sea area of Central Vietnam, showing BSR at depths of 1-2 seconds (TWT)

16 Conditions and prerequisites (7) Gas-geochemical anomaly The anomalies of gas migration along the fault is also quite clear on the petroleum seismic data and on gas geochemical sampling documents. At the Phu Khanh basin, a large air flow moving from deep to the sea floor can be observed on the seismic profile. This shows that gas resources in this area are derived from the deep part.

17 Move forwards In order to motivate the research and investigation on gas hydrate potential in Vietnam, it is necessary to mobilize a great investment for capacity building based on training for high quality human resources, enhancement of international cooperation and investment on equipment, technology capacity in this new field. Activities of research and investigation of gas hydrate potential should be conducted in parallel with the research and investigation activities iii of marine geology and minerals, with ihfocus on oil and gas. It is scientific basis for conducting selection of research and investigation of gas hydrate as well as for zoning gpotential areas of gas hydrates. Research and investigation activities will be firstly conducted on the selected marine areas according to a network by a system of consistent and uniform methods.

18 Move forwards (2) The programs of research and investigation can be generally conducted via three main steps as follows: - Step 1: Basic research and investigation on gas hydrate in prospecting areas (based on results of previous basic investigation on geology gy and minerals, marine resources and environment). - Step 2: Zoning of high potential of gas hydrate and drilling test. - Step 3: Studying and developing techniques of gas hydrate exploration and production test.

19 SOME SUGGESTIONS Selectively inheriting from the world methods on gas hydrate research and investigation for over the last 40 years, it is recognized that we should focus on international cooperation with experienced agencies such as CCOP, etc. in the field of gas hydrate research and investigation. This is also the fastest way for Vietnam to achieve the expected results on capacity building in the process of researching, investigating and prospecting gas hydrates.

20 Thank You very much!