ĐỊA CHẤT, ĐÁNH GIÁ TIỀM NĂNG CẤU TẠO PHẢ LẠI

GEOLOGICAL WELL PROPOSAL 107-PL-5X PSC Blocks 103&107 Offshore, S.R Vietnam Prepared by: _ Date: _ Tran Duc Ninh Snr Geologist _ Nguyen Duong Trung Date: _ Snr Geophysicist Verified by: _ Nguyen Van Thang Date: _ Deputy Exploration Manager Approved by: _ Tang Van Binh Date: Exploration Manager _ Tran Nhu Huy Deputy Director Date: TABLE OF CONTENTS TABLE OF CONTENTS LIST OF FIGURES LIST OF TABLES LIST OF APPENDICES EXECUTIVE SUMMARY I INTRODUCTION BLOCKS 103&107 I.1 REGIONAL SETTING I.3 EXPLORATION HISTORY 11 II SEISMIC INTERPRETATION 14 II.1 3D SEISMIC DATA QUALITY 14 II.2 SEISMIC TO WELL CORRELATION .14 II.3 SEISMIC INTERPRETATION 15 II.4 TIME – DEPTH CONVERSION AND MAPPING RESERVOIR 17 III PHA LAI GEOLOGICAL EVALUATION 18 III.1 PROSPECT DESCRIPTION 18 III.2 PETROLEUM SYSTEM 18 III HYDROCARBON RESOURCES ESTIMATION AND RISK ASSESSMENT 20 IV 107-PL-5X WELL PROPOSAL 22 IV.1 STRATIGRAPHY PROGNOSIS 22 IV.2 WELL PROPOSAL LOCATION AND TRAJECTORY 24 IV.3 WELL TOTAL DEPTH “TD” CONCEPT 24 IV.4 DRILLING HAZARDS 25 IV.5 PORE PRESSURES AND TEMPERATURE PROGNOSIS 26 V FORMATION EVALUATION PROGRAM .26 V.1 MUD LOGGING AND SAMPLING 26 V.2 SIDEWALL CORES 28 V.3 LOGGING PROGRAM .28 V.4 WELL TESTING 29 VI REPORTING AND ADDRESSES FOR COMMUNICATION 31 VI.1 REPORTING 31 VI.2 ADDRESSES FOR COMMUNICATION & DATA TRANSMISSION 31 LIST OF FIGUR Figure a: Location of Pha Lai prospect in Block 107, Song Hong Basin 34 Figure b: Oil Trend Expectance (Hydrocarbon Potential) at Block 107 34 Y Figure 1.1: The location of Song Hong basin and surroundings 35 Figure 1.2: Major fault system in controlling the Tertiary sedimentation and deformation of the Song Hong basin 35 Figure 1.3: General Stratigraphy of the Central Song Hong Basin 36 Figure 1.4: Structure Elements in the Block 103-107 37 Figure 1.5: Play Types in the Block 103-107 (2D seismic line gpgt93-203) 38 Figure 1.6: Location of drilled wells in Bocks 103 and107 38 Figure 1: Pha Lai 3D Seismic area .39 Figure 2: Seismic data quality overview 39 Figure 3: Geological structure changes from proposed Pha Lai -1X to 107T-PA-1X well 40 Figure 4: Ham Rong – 2X well ties to seismic 40 Figure 5: Random line seismic through Ham Rong, Yen Tu, Ha Long and Block 107 .41 Figure 6: Regional stratigraphic column 41 Figure 7: Eight unconformities interpreted in the 3D seismic area 42 Figure 8: U100 time structure map 42 Figure 9: U150 time structure map 43 Figure 10: U170 time structure map 44 Figure 11: U200 time structure map 45 Figure 12: U300 time structure map 46 Figure 13: U350 time structure map 46 Figure 14: U400 time structure map 47 Figure 15: U500 time structure map 48 Figure 16a: Time Depth conversion statistics 48 Figure 16b: Time Depth conversion function 49 Figure 17: Depth structure map of U100 at Pha Lai prospect area 49 Figure 18: Depth structure map of U150 at Pha Lai prospect area 50 Figure 19: Depth structure map of U170 at Pha Lai prospect area 50 Figure 20: Depth structure map of U300 at Pha Lai prospect area 51 Figure 21: Depth structure map of U350 at Pha Lai prospect area 51 Figure 22: Depth structure map of U500 at Pha Lai prospect area Figure 1: Source rock characterization in the 102-103-106-107 blocks 52 Figure 2: Structures of reservoirs in the Pha Lai Prospect 53 Figure 3: Model of Migration and Oil/Gas charge in the Block 102-106-103-107 53 Y Figure Prognosis lithology column of well 107-PL-5X 54 Figure 2: Surface location on overly closure map in the Pha Lai Prospect .55 Figure 3: Inline 3030 through 107-PL-5X with well path 55 Figure 4: Xline 1826 through 107-PL-5X with well path 56 Figure 5: Pore Pressure and Temperature prediction for 107-PL-5X 56 LIST OF TABL Table a: Summary information of 107-Pha Lai -1X (107-PL-5X) Well Y Table 1: Summary information of plays in Blocks 103 and 107 11 Table 2: Summary of drilled wells in Blocks 103 and 107 12 Table 1: Seismic characteristic of respective horizons Table 1: Pre-drill OIIP - Pha Lai Prospect 21 Table 2: Pre-drill GIIP - Pha Lai Prospect 21 Table 3: Risk assessment for Pha Lai prospect 21 Y Table 1: Prognosis of Horizon Tops at well 107-PL-5X 22 Table 1: Proposed cutting sampling program .27 Table 2: Sample requirement and distribution 27 Table 3: Logging program for 107-PL-5X Well 28 Table 4: List of log data and distribution 29 LIST OF APPENDICES Appendix Regional Seismic Cross section Appendix Seismic Cross section Inline 3030 through 107-PL-5X Appendix Seismic Cross section Xine 1826 through 107-PL-5X Appendix Depth structure Map of U170 Appendix Depth structure Map of U300 Appendix Depth structure Map of U350 Appendix Depth structure Map of U500 Appendix 107-PL-5X Well Montage EXECUTIVE SUMMARY Following the 2012 WP&B for Blocks 103&107 approved on 20 th Jan 2012, under the master plan of work program for 1+1 wells (1 firm and contingent), the Operator will drill firm well in September, 2012 After several Technical Workshops, all the partners agreed that the Pha Lai as the first priority prospect to be drilled This well will be credited as the commitment well in the 2nd Exploration Phase of the PSC Blocks 103 & 107 Pha Lai prospect is located in the Eastern of Block 107, Song Hong Basin, Northern S.R.Vietnam offshore (Figure a) This prospect is about 140 km southeast from Hai Phong City with the water depth about 40 meters The objectives of 107-PL-5X well include: - The primary target is the Pre-Tertiary karstified and fractured Carbonate Basement The secondary target is the clastics in the Oligocene and Miocene formations Structural interpretation, mapping and prospect delineation for the Pha Lai structures are based on the 1,138sq.km 3D seismic acquired in 2011 The Pha Lai prospect was showed nearly four-way dip closure on U170 (Upper Miocene), U300 (top Oligocene) and controlled by NW-SE trend faults It is three-way dip closure at the U350 (top of intra Oligocene) and two-way dip closure at U500 (top Pre-Tertiary basement) Base on the seismic correlation in the area, the Pha Lai prospect is expected in the same Ham Rong – Yen Tu oil trend which has been proved by oil discoveries of Ham Rong and Yen Tu wells The hydrocarbon potential (Most Likely-P50) in the carbonate basement is estimated 153mmbbl in case of oil/ or 438bcf in case of gas The hydrocarbon potential in clastic reservoirs is estimated 58mmbbls in case of oil/or 93bcf in case of gas The prospect probability of success (POS) is conjectured around 0.28 for basement, 0.25 for Oligocene and 0.28 for Miocene Well 107-PL-5X is designed as vertical well with proposed TD of 3980mTVDSS However, the actual final TD will be decided depend on drilling operation, hole condition and hydrocarbon shows as well as other factors If necessary, the revision of TD will be discussed and finalized among PVEP-POC and the partners during drilling operation Table a: Summary information of 107-Pha Lai -1X (107-PL-5X) Well Well name 107-Pha Lai-1X (107-PL-5X) Area North Song Hong Basin, Offshore Vietnam Block 107 Well classification Vertical – Exploration Well Lat 19° 51’ 24.797” N Location Co-ordinates Long 107° 27’ 08.276” E X = 756,815.0 mE Y = 2,197,515.0 mN Projection UTM-Zone 48N Central Meridian 1050 Datum WGS 84 False Easting 500.000 False Northing 0.000 Scale factor 0.999600 Seismic lines Inline 3030 and Xline 1826 Distances to shoreline 150 km far from PTSC Dinh Vu Supply Base Proposed TD 3,980 mTVDss/ 4,010 mMD Operator PVEP POC Rig Contractor Transocean Rig name Key Hawaii Rig type Jack up Water depth 40 m below Mean Sea Level (MSL) DFE 30 m Objectives - The primary target: Pre-Tertiary Kastified and Fracture Carbonate Basement - The second target: Clastic Reservoir (Miocene and Oligocene) Spudded day September 2012 Number of days (prevision) 103 days (included 24 days for towing Rig) I BLOCKS 103&107 INTRODUCTION I.1 Regional Setting Blocks 103 & 107 are located in the Northern part of Song Hong Basin and SE of Sub basin Bach Long Vi, Northern Vietnam offshore and approximately 140 km Southeastern of Hai Phong Port with water depth ranging from 30 to 45 meters (Figure 1.1) Song Hong basin is an elongated basin trending in NW-SE direction with dimension of about 650 km length, about 150 km width and more than 10 km of sediment thickness at its depocentre The basin is surrounded by other basins such as Bach Long Vi sub basin in the Northeast; Southeast Hai Nam and Hoang Sa basins in the Southeast and at the southern end is the Phu Khanh basin The onshore part of Song Hong basin is known as the Hanoi Trough Structurally, Song Hong basin is a valley shaped depression bounded by two main northwest to southeast trending faults These northwest to southeast trending faults are believed to be the seaward extension of the very prominent strike slip fault in the region known as Red River Fault Zone (Zhen Sun at.el., 2003.) The two main faults in the offshore part that controlled the Tertiary sedimentation and the deformation of Song Hong basin are known as Song Chay and Song Lo faults The types and the direction of the strike slip movements of these faults, which is believed to play a major role in the formation and evolution of Song Hong basin become the subject of debates (Figure 1.2) The main rifting phase occurred from Eocene to the end of Early Oligocene During this phase, grabens and half-grabens were formed in Song Hong Basin which later filled up by the fluvial and lacustrine deposits (Figure 1.3) In late Oligocene time, the spreading out of East Sea to the southeast has caused compression in the Song Hong Basin This has resulted to the inversion and uplifting of horsts and grabens in the Song Hong basin The inversion has created a pop up structures on overlying younger sediments followed by active erosions during late Early Oligocene time that cut significant amount of earlier deposited Oligocene sections The angular unconformity as a result of the erosions in the late Oligocene time is clearly seen on seismic lines in Blocks 103 & 107 This unconformity is believed to be a major break-up unconformity separating the syn-rift and post-rift sections The post rift phase was started in the Middle Miocene when basin was undergone large-scale subsidence During the post rift phase, coastal plain, deltaic and marginal marine facies, containing sandstones of good reservoir potential were deposited (Figure 1.3) The geodynamic and tectonic evolution in the area has provided the structural framework for the hydrocarbon trapping mechanism in the Song Hong basin The main structural elements in the Blocks 103&107 are summarized as follows (Figure 1.4):  The Monocline Basement High dominates in the western - northwestern part of Block 103  The Bach Long Vi Basement High occupies in the north of Block 107  Pha Lai – Ham Rong - Ha Long - Yen Tu - Chi Linh -Tien Lang Ridge, extending up to the B10-STB-1X area onshore  The “Central Graben“ is bounded by the Song Lo Fault to the north and Song Chay Fault to the south in the eastern – southeastern Block 103 and western, southern Block 107  Inversion structures are found in the north – northeast of Block 103 and northeast of Block 107 In additional, there is another point of view that the sub basin named Bach Long Vi exist on the Northeast of Song Lo fault The techtonic, stratigraphy and the structures of Bach Long Vi sub-basin are being studied by PetroVietnam, and the possible cluster includes Pha Lai, Tam Diep and Nga Son prospects are located in this Sub-basin(?) I.2 Hydrocarbon Play Types There are six (06) types of plays existing in Blocks 103 and 107 (Figure 1.5) - (1) Fractured and karstified carbonaceous basement (Buried hills) (2) Oligocene-Miocene sandstones Draped over Basement High and/or Paleogene High (3) Layering Oligocene sandstones associated inverted structures (4) Layering Miocene sandstones associated inverted structure (5) Oligocene– Miocene sandstones associated with stratigraphic pinch-outs (6) Miocene sandstones in the channel fill sequence (stratigraphy trap) In study area (Northeast of Block 107), types of plays are proposed: type (1) of Carbonate Basement; type (3), (4) and (6) of Clastic Reservoir (Table 1.1) Table 1: Summary information of plays in Blocks 103 and 107 107-PL-1X 107T-PA-1X Figure 7: Eight unconformities interpreted in the 3D seismic area Figure 8: U100 time structure map Figure 9: U150 time structure map Figure 10: U170 time structure map Figure 11: U200 time structure map Figure 12: U300 time structure map Figure 13: U350 time structure map Figure 14: U400 time structure map Figure 15: U500 time structure map Figure 16a: Time Depth conversion statistics Figure 17b: Time Depth conversion function Proposed 107-PL-1X Figure 18: Depth structure map of U100 at Pha Lai prospect area Proposed 107-PL-1X Figure 19: Depth structure map of U150 at Pha Lai prospect area Figure 20: Depth structure map of U170 at Pha Lai prospect area Figure 21: Depth structure map of U300 at Pha Lai prospect area Figure 22: Depth structure map of U350 at Pha Lai prospect area Figure 23: Depth structure map of U500 at Pha Lai prospect area Figure 1: Source rock characterization in the Blocks 102, 106, 103 and 107 Figure 2: Structures of reservoirs in the Pha Lai Prospect Figure 3: Model of Migration and Oil/Gas charge in the Blocks 102, 106, 103 and 107 Figure Prognosis lithology column of well 107-PL-5X Figure 2: Surface location on overlay closure map in the Pha Lai Prospect Figure 3: Inline 3030 through 107-PL-5X with well path Figure 4: Xline 1826 through 107-PL-5X with well path Figure 5: Pore Pressure and Temperature prediction for 107-PL-5X