Blocks offered in Sri Lanka s Second Licensing Round

Transcription

1 Blocks offered in Sri Lanka s Second Licensing Round

2 Sri Lankan Main Basins Cauvery Basin Cauvery Deep Water sub-basin Mannar Basin 2

3 Structural Framework Sri Lanka Basins Cauvery & Mannar Basins were initiated as rifted basins in Gondwanaland, producing NE SW structural grain Two thermal events have controlled basin development & burial history: Gondwana breakup & start of sea floor spreading (~99 My) Breakup of India & Madagascar & sea floor spreading from Central Indian Ridge (~64 My) Seismic data confirms that NE-SW structural grain extends into Mannar Basin Up to 5500 m of Upper Jurassic to Recent sedimentary section, possibly underlain by Triassic (Karoo) Coal Measures, providing gas source potential Mannar Basin has Late Cretaceous to Tertiary objectives, with deeper potential in Late Jurassic Early Cretaceous syn-rift section.

4 Tectonostratigraphic Framework (Cauvery & Mannar Basins) Stratigraphic columns and tectonic framework interpretations of Cauvery & Mannar Basins Note that the Tertiary section in Mannar Basin is more complete than in Cauvery Basin Two episodes of basaltic extrusion in the Mannar Basin during the Cretaceous An early interpretation of Mannar Basin suggested that Turonian igneous unit (the BHF in Pearl 1) well represented Cretaceous oceanic crust which was overlain by Tertiary section This interpretation led to Mannar Basin being written off as non-ive Cairn Energy s 2011 discoveries have proved that there is a working petroleum system in Mannar Basin and that it is highly ive 4

5 Cairn India s View 5

6 Line SL01-1 through Dorado North well

7 Available data in Cauvery Basin: Well data Six wells have been drilled in the Sri Lankan sector of the Cauvery Basin, three onshore Mannar Island and three offshore. Basic details of the wells are provided in the following table: Adam s Bridge archipelago Well Name Onshore Water Offshore Terrain Latitude Longitude Depth Meter Water Depth Feet Ground Elevation Meter Ground Elevation Feet Operator Name Spud Date Init Drill End Date Well Status Content Td Feet Td Meter Pesalai 1 Onshore Land N 09`04'07.960" E 079`48'10.420" Ceylon Petroleum Corp 07/02/74?/12/1974 P&A gas shows Pesalai 2 Onshore Land N 09`04'25.380" E 079`49'01.300" 2 6 Ceylon Petroleum Corp 27/04/75 16/08/75 P&A oil & gas shows Pesalai 3 Onshore Land N 09`05'03.790" E 079`48'29.900" 3 10 Palk Bay 1 Offshore Shelf N 09`19'03.840" E 079`43'21.540" Delft 1 Offshore Shelf N 09`40'01.236" E 079`33'27.216" Pedro 1 Offshore Shelf N 09`53'05.360" E 079`36'25.910" Ceylon Petroleum Corp Marathon Petroleum Marathon Petroleum Citco Sri Lanka Petroleum Corp 10/01/76 24/04/76 P&A dry /06/76 06/08/76 P&A dry /08/76 09/09/76 P&A dry /11/81 21/12/81 P&A dry Well summaries for all wells are 7 available in the data room..

8 Seismic Data in Mannar Basin 2350 km 2 3D in Block SL All seismic km 2D Mannar Basin only 2350 km 2 3D NB. Old Block 11 included Palk Straight (Cauvery Basin) and the northern part of Mannar Basin. Data acquired in Block 11 have not been included, so that total seismic in the Mannar Basin may be greater than shown. 8

9 Well data in Mannar Basin: Pearl 1 Pearl-1 was the only well drilled in the Sri Lankan sector of the Mannar Basin prior to Cairn s wells in Block SL (in ) Pearl 1 was drilled by Cities Service in 1981 to test a Late Cretaceous structural (fault) trap. Tertiary drape provided a secondary objective The well penetrated thick Late Cretaceous sandstones (between 2,194.6 m & m) and a Basal Cretaceous sandstone (between 2926 m & m) There were no shows in either sandstone The well TD d in what was described as igneous (olivine diabase) rocks which was interpreted as basement Similar rocks were encountered in Mannar-1, -1A, located 68 km to NW, in the Indian sector of Mannar Basin, leading to the misconception that Mannar Basin was underlain by oceanic crust Pearl 1 failed to test the syn-rift section now interpreted to lie below the well TD Cities cited lack of charge as reason for failure but NewSouth Global suggest that lack of top seal or fault breaching are more likely causes of failure.? Fault cut 9

10 Ceylon Basin: Location, seismic & well data Ceylon Basin is located to south & south-west of Sri Lanka No wells have been drilled in the Ceylon Basin There are no interpretation reports available for the Ceylon Basin There are very few seismic lines available in the Ceylon Basin; the only data were acquired in 1976, as part of Western s Circum Island spec survey Western s Line 17, a NW SE line off the southern coast of Sri Lanka, is illustrated (as reprocessed by CGL in 2012). Western Geophysical s Circum Island spec survey,

11 Block Summary Sheets Interpretation Reports Expanded Basin Descriptions Gravity Maps Well Reports for: Delft Palk Bay Pearl 1 Pedro Pasalai 1 Pasalai 2 Pasalai 3 Data Pack Contents