Presentation on theme: "COMPARISON BETWEEN KENYA TERTIARY RIFT AND LIAODONG BAY DEPRESSION 11th Africa Oil & Gas, Trade & Finance Conference & Exhibition Kenya 2007 23 th -25."— Presentation transcript:
COMPARISON BETWEEN KENYA TERTIARY RIFT AND LIAODONG BAY DEPRESSION 11th Africa Oil & Gas, Trade & Finance Conference & Exhibition Kenya 2007 23 th -25 th May 2007 Nairobi, Kenya 11th Africa Oil & Gas, Trade & Finance Conference & Exhibition Kenya 2007 23 th -25 th May 2007 Nairobi, Kenya Wu Keqiang Senior Geologist Research CNOOC Beijing China Tel: 010-84525363 Email: Wukq@cnooc.com.cn NOT AN OFFICIAL UNCTAD RECORD
2 ACKNOWLEDGEMENTS Colleagues at CNOOC CNOOC International Limited Science and Technology Development Department, CNOOC Research CNOOC 11th Africa Oil & Gas, Trade & Finance Conference & Exhibition
3 Introduction of Kenya Tertiary Rift and Liaodong Bay Depression Petroleum Geological Comparison of Kenya Tertiary Rift and Liaodong Bay Depression Advice and Conclusion OUTLINE
4 Introduction of Kenya Tertiary Rift and Liaodong Bay Depression - Location and Exploration - Why Liaodong Bay Depression Petroleum Geological Comparison of Kenya Tertiary Rift and Liaodong Bay Depression Advice and Conclusion OUTLINE
5 The Location of Kenya Tertiary Rift Kenya Tertiary Rift locates in the western part of Kenya, develops in the eastern branch of the East African Rift System.
6 The Exploration Statue of Kenya Tertiary Rift FRONTIER AREA Aera : 38,904 km 2 Wells : 2 Seismic 2-D: 7,652 km Loperot 1: located in the southern part of the Lokichar Trough. Encountered two lacustrine shale intervals with very good source rock potential. Recovered some 9 liters of 29° API crude during a DST. Eliye Springs 1: was drilled in the southwestern part of the Turkana Graben. The well was abandoned as dry. Loperot 1 Eliye Springs 1 From nation oil corporation of Kenya
7 The Loacation of Liaodong Bay Depression BOHAI BAY BASIN LIAODONG BAY DEPRESSION Liaodong Bay Depression (LBD) locates on the northern part of Bohai bay basin, China, covers an area about 15,300 square kilometers.
8 The Exploration Statue of Liaodong Bay Depression JZ31-6 120 exploratory and delineation wells were drilled, 79 wells got oil flow, 9 oil & gas fields and 19 oil beared structures have been discovered. The geological success rate is 66%. Aera : 15300 km 2 Wells : 120 Seismic 2-D: 18,000km
9 Analog, why LBD? Comparative analysis is the most popular way at the beginning of studying a frontier area. 3 reasons exit, why Choosing the Liaodong Bay Depression (LBD) as the analog to compare with KTR. Basin type is similar-rift Shape is similar-stripe Framework of basin is similar-half grabens Comparing the basin origin, the petroleum geology and accumulation process of KTR with LBD, may obtain several good advices and ideas for exploration in KTR.
10 Tan-Lu fault system Liaodong Bay Depression Xu Shouyu,2005 The Basins Type Kenya tertiary rift, is a new episode succeeded the Cretaceous-Paleogene one. This mainly N-S trending rifting phase has active since the Eocene and is responsible for the creation of a string of half graben sub-basins. Liaodong Bay Depression sits astride the Tan-Lu fault system of eastern China, one of the world's largest strike- slip fault systems. From nation oil corporation of Kenya
11 The Basin Shape Basin BoundaryTan-lu fault A B section Shore line risesag ① ② ③ ④ ⑤ ① Liaoxi sag ② Liaoxi rise ③ Liaozdong sag ④ Liaodong rise ⑤ Liaozhong sag A B The structure framework of Liaodong Bay Depression Both of KTR and LBD are all narrow, elongated system of normal faults. From nation oil corporation of Kenya
12 Precanbrian basement E-E.N 1 Liaoxi sag Liaoxi Uplift Liaozhong sag Liaodong Uplift Liaodong sag Zhang Gongcheng The structural framework Major extensional faults in the KTR define separate Basins with distinctive structural and geological setting. Five basins are included in KTR, Turkana onshore, Kerio, North Lokichar, Lokichar, South Kerio Trough. LBD consists of 3 sub-basins(sags) and 2 rises, Liaoxi sag,liaozhong sag,liaodong sag, liaoxi rise, liaodong rise. From nation oil corporation of Kenya
13 Introduction to Kenya Tertiary Rift and Liaodong Bay Depression Petroleum Geological Comparison of Kenya Tertiary Rift and Liaodong Bay Depression - Structure Evolution - source rock - Reservoir and Cap - Habitat of LBD - Geological risks of KTR Advice and Conclusion OUTLINE
14 LIAODONG BAY DEPREESION RIFTING STAGE Basin Time PRESENT TERTIARY CRETACEOUS BASEMENT FAILED REACTIVE Late Early No or few deposits Structural Evolution During the tectonic evolution, KTR underwent the rifting stage Only, which may initiated from Eocene, at the end of Neogene, regional uplifting occurred. LBD began its evolution in Paleocene, ungerwent 3 stage such as, rifting stage, failed rift stage and reactive stage. From nation oil corporation of Kenya
15 The petroleum geology- source rock Two major lacustrine shale source rock intervals, which were penetrated by Loperot-1, in KTR, aged Miocene and Oligocene respectively, are low to high mature. The major source rock in LBD, is Shahejie Formation, lacustrine shale, which was aged Eocene. Lokhone shale Lopreot shale From nation oil corporation of Kenya
16 ITEMS KENYA TERTIARY RIFT LIAODONG BAY DEPRESSION AgeMiocene, OligoceneEocene Thickness(m)About 200About 400-1200 TOC(%)2.86(Ave.) 1.02-7.691.02-2.32 Type of Kerogen II HI508(Ave.) 186-748290-454 LithofaciesLacustrine shale Degree of Maturity Lokhone:low-Mature Loperot:Mature to high mature Mature to high mature DataDaniel M. Jarvie, 2005CNOOC The petroleum geology- source rock Besides the thickness penetrated by wells, several characters of source rock in KTR are similar with LBD’s. Some items of KTR are better than LBD’s.
17 The petroleum geology- source rock From the classification and potential assessment diagram of organic matter, both of organic matters in KTR and LBD, belong to type II, and lot of samples distribute in good to excellent area.
18 Source rock in Lokichar basin Potential generating capacity of Lokhone Shale Member is estimated at 10.5 billion barrels. Given that about 40% of the shale volume is at mid to post mature levels this suggests the Lokhone Shale Member could have generated about 4 billion barrels of oil. After Marine and Petroleum Geology 21 (2004) 63–78 Loperot Shale Member, which is mature to high-mature. Lokhone Shale Member, which is low-mature to mature. From nation oil corporation of Kenya
19 The petroleum geology- reservoirs and seals Reservoir and cap assemblages I II III On the base of two shale segments, III reservoir and cap assemblages were identified in KTR. 3 assemblages exit in LBD, E2d, E2-3s, Pre-T(carbonate and volcanic). From nation oil corporation of Kenya
20 The oil quality KTR:Tested oil ~ 29 o API (0.883) LBD:heavy oil API: 17.4 o (Ave.) API<22.3(0.92): 86% The oil quality of KTB is better than LBD. From nation oil corporation of Kenya
21 The oil habitat of LBD-source, play 1. 1. The favorable sag controls the fields distribution. About 80% reserves distribute around Liaozhong sag. 2. 2. The favorable assemblage controls the most favorable play. Ed, the major play in LBD, deposited almost 90% reserves. Liaoxi sag Liaozhong sagLiaodong sag Zhang Gongcheng Liaozhong sag
22 Liaoxi Sag Liaoxi Low Uplift By Li Weilian Liaozhong Sag Liaodong Uplift Liaodong Sag Fault block Anticline pool structural-stratigraphic buried hill pool Turbidite pool Lithologic pinchout 4 types of oil accumulation zones:Rise, Steep slope zone, gentle slope zone, Inner graben. Almost 90% reserves deposit in gentle zones and rises. Sand body and fault made up of the major transport system by which oil and gas charged into the pools. Multiple types of oil pools are found in LBD. The oil habitat of LBD-zone, pool rise Gentle slope Steep slope Inner sag
23 root mean square(RMS) amplitude of on-horizon slice Zhao Rumin ， 2005 Absorption analysis profile Liu Zhibin ， 2006 Produced 11.7 mmcf/day in DST, (choke: 11.91mm) Proved gas layer perspective gas layer
24 The geological risks of KTR- source rock The distribution of two layers source rock is limited. From nation oil corporation of Kenya
25 Heat Flow Distribution in Kenya Lokicharbasin Anzabasin The maturity of source rock influenced by local heat flow, such as lava, obviously, it is difficult to identify the range of active pods. From nation oil corporation of Kenya
26 The geological risks of Kenya Tertiary Rift During late Neogene to present, after oil accumulated, regional uplifting and erosion occurred, so another risk is preservation condition. From nation oil corporation of Kenya
27 Introduction to Kenya Tertiary Rift and Liaodong Bay Depression Petroleum Geological Comparison of Kenya Tertiary Rift and Liaodong Bay Depression Advice and Conclusion - Three step: source-transport-play - The critical technology: seismic OUTLINE
28 In LBD, the favorable oil generating sag (Liaozhong sag) control the oil field distribution. the favourable reservoir rock and cap rock assemblage (Ed) controls the rich-play. The gentle zones and rises controls almost 90% reserves. Multiple oil pools are found in LBD In the frontier area, such as KTR, according to the exploration program and the primary factor controlling the oil distribution of LBD, 3 points should be noticed during exploration activity. looking for the favorable basins and grabens looking for the favorable reservoir and cap assemblage looking for the favorable oil accumulating zones.
29 The distribution of basins in KTR 5 basins Lokichar basin is the best one. area thickness Source rock layer Oil seep or show From nation oil corporation of Kenya
31 EROSION Among the three reservoir and cap assemblages, the lower assemblages may be the best one. From nation oil corporation of Kenya
32 Lava and Seismic technology At least two periods volcanics exist in KTR. They covered the deposits below them, brought the shielding effect on seismic profiles. In KTR, the structural framework cannot be divided clearly, the lithofacies cannot be identified reliably, because of the shielding effect. From nation oil corporation of Kenya
33 Eliminating the shielding effect of lava, can obtain better seismic image. Thus the uncertainty and risk during exploration process can be decreased. So advanced seismic acquisition and processing technology is necessary. Improve the reliability of sediment facies. Study the framework of basin. Improve the reliability of trap interpreted from seismic datas.
34 CONCLUSION Kenya tertiary rift is similar with Liaodong bay depression in basin type, shape and framework. They are differences in structure evolution and some factors of petroleum geology. Kenya tertiary rift have good source rocks. The area of active source rocks and the preservation post oil charging are geological risks for exploration. The latter is the worst one. The oil habitat of Liaodong bay depression is useful for Kenya tertiary rift during exploration activity. The first step is to identify the favorable generating grabens, then to find the favorable area having good preservation condition. Improve the seismic quality can decrease the geological risks and costs.
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