2.2.4 SOUTH VENTURE FIELD

Transcription

1 Deveopment Pan Appication SOUTH VENTURE FIELD Fied History In 983, the discovery we South Venture O59 was dried to a tota depth of 66 metres. Mutipe, verticay stacked hydropressured and overpressured sandstone gas accumuations were encountered, testing at fowrates up to 59 E3M3/d. Hydropressured reservoir horizons occur from 3926 to 4266 metres in the O 59 we. Overpressured gas accumuations occur between 446 and 554 metres. Figure iustrates the South Venture Sand 2 depth structure map. WEST VENTURE C62 SABLE ISLAND 59 4! VENTURE H22 VENTURE B SOUTH VENTURE O Km Figure : South Venture Fied Top Sand 2 Structure Map Contour Interva: 2 Metres 2 Mi Structura Configuration The South Venture structure is a ow reief roover anticine situated on the downthrown side of a major eastwest trending growth faut. At the top Sand 2 hydropressured horizon, the structure is approximatey eight kiometres by three kiometres, encompassing an area of 23 square kiometres, with metres of vertica cosure. Gross cosure is estabished by structura sadde spipoints to the east and west of the South Venture structure. Chapter 2: Geoogy, Geophysics and Petrophysics

2 5 25 Deveopment Pan Appication Geoogy The South Venture reservoir section consists of interbedded shaes, sitstones, sandstones, and occasiona imestones or highy cacareous sandstones. As in the Venture Fied, this cycic sedimentation is interpreted to be the resut of deta progradations of Late Jurassic and Eary Cretaceous age, the deposits of which are assigned to the Mic Mac and Lower Missisauga formations. Hydropressured gas was tested in five independent reservoir horizons. Figure is a net pay map of one of these horizons, the Sand 2 reservoir. Net pay in the O59 we at this horizon is 4.5 metres. The free water eve eevation estimate of 3936 metres subsea is based on an assumed 8 percent fiup voume. Gas is inferred to be trapped by a combination of roover cosure and faut cosure (DPA Part 2 Ref. # ). WEST VENTURE C62 SABLE ISLAND 59 4! VENTURE B VENTURE H SOUTH VENTURE O ESTIMATED FREE WATER LEVEL 3936 METRES Km Mi Figure South Venture Fied Sand 2 Net Pay Thickness Map Contour Interva: 5 metres Two overpressured sandstone horizons, sands and 8, tested gas in the 59 we. These horizons have ow porosity as demonstrated by wireine ogs, and exhibited significant pressure drawdown during dristem testing. These deep overpressured accumuations are not currenty incuded in the Project. There were no cores taken in the O59 we, and attempts to recover Repeat Formation Test (RFT) data were unsuccessfu, argey due to too seating probems. Chapter 2: Geoogy, Geophysics and Petrophysics

3 Deveopment Pan Appication Reservoir Zonation Using O59 wireine og response, and correations to the Venture Fied wes, the hydropressure section was subdivided into sandstone packages, and numbered from zero to six. Reservoir sandstones in the South Venture hydropressure section are younger than the Venture Fied reservoirs. Based on these correations to Venture and continuous seismic refectors within the South Venture structure, sandstone continuity in the hydropressured section is anticipated to be favourabe. The reservoir nomencature for South Venture is shown in Figure Depth, metres, subsea 4 NORTH O59 GR SOUTH Sand 2 Sand 3 Sand 4a Sand 5 45 Sand 6 TOP OVERPRESSURE 5 Sand Sand 8 55 Project Sandstones NonProject Sandstones Vertica Exaggeration 4 x 2 3 km 2 mies 6 N O59 km Figure : South Venture Schematic Structura Crosssection Chapter 2: Geoogy, Geophysics and Petrophysics

4 252 Deveopment Pan Appication Geophysics Seismic Database The South Venture Fied is covered by essentiay the same vintages of seismic data as the Venture Fied. A summary of acquisition and processing detais for severa of these datasets is incuded in Tabe The data density and quaity at the norma pressured eve sands is good to very good. There is ony one strike ine. The synthetic seismogram from the O59 ties very we with the seismic at both mapped horizons. In the overpressured section, frequency content and horizon continuity has decreased but mapping confidence remains quite high. The depth structure maps used for gas in pace estimates are based on the 2D seismic data iustrated in Figure Tabe : South Venture Acquisition and Processing Summary Data Survey Incorp. Acq. Acq. Proc. Fied Proc. Type Name In Study Date Stye Date Kms Detais Comments 2D 8624M34E Yes 983 Marine fod Generay good to very good Decon before quaity. Deteriorating with depth and after stack, FD migration 2D R No 983 Marine fod Fair to good quaity Desig, Decon after stack FD migration 2D 8624M34E No 98 Marine fod Good quaity data, Desig, ower frequency Decon after stack, FD migration 2D 8624M335E No 98 Marine fod Generay good quaity data, Desig, ower frequency Decon after stack, FD migration 2D 8624M333E No 99 Marine fod Fair to good quaity DBS, Decon after stack, FD migration Chapter 2: Geoogy, Geophysics and Petrophysics

5 Deveopment Pan Appication 253 " "! SOUTH VENTURE SDL Sabe Isand Figure seismic ine Km. 2 3 Mi. N Figure : South Venture Seismic Database Map Time Interpretation The maps used for the gas in pace cacuations at South Venture are based on time and depth structure maps made from the 983 data. The entire 983 survey consists of 52 ines for a tota ength of 356 ine kiometres. There is ony one strike ine in the survey that crosses the South Venture Fied. This ine runs from east to west, just south of the crest of the structure in the hydropressured section and through the O 59 we. The dip ines have an east to west ine spacing of approximatey 3 metres over the crest and fanks of the structure. A seismic ine representative of the data quaity and iustrating the fied geometry is incuded as Figure and its ocation is shown as a bod dashed ine in Figure Chapter 2: Geoogy, Geophysics and Petrophysics

6 254 Deveopment Pan Appication South South Venture O59 (projected) North 2.6 Upper Missisauga #3 Sand 3.2 #8 Sand 3.4 Y Limestone Figure : South Venture Seismic Line The South Venture interpretation was generated on paper sections that were hand timed, posted and contoured. A checkshot survey corrected synthetic seismogram, generated at the O59 we by convoving a minimum phase waveet with an acoustic impedance series derived from the wireine og sonic and density information, was used to tie we ithoogy to the seismic data. Two horizons were mapped in the hydrocarbon bearing portion of the fied; one in the hydropressured section and one in the overpressured section. The Upper Missisauga Event corresponds to the top of the South Venture Sand 2 and was used to generate maps for Sands 2, 3, 4, 5 and 6. The second time event mapped, corresponds to the top of overpressured South Venture Sand 8 at O59. The mapping horizons are iustrated in Tabe Detaied maps are incuded in Part Two (DPA Part 2, Ref. # ). Tabe : South Venture Mapping Horizons FIELD SOUTH VENTURE 59 MAP HORIZON Depth TWT (M, ss) (sec) UPPER MISSISAUGA #8 SAND Chapter 2: Geoogy, Geophysics and Petrophysics

7 Deveopment Pan Appication Depth Conversion The depth conversion at South Venture used the same technique and veocity database as that described in Venture Section Time structure maps for two horizons; the Upper Missisauga (Top of Sand 2), and the Top of Sand 8, were digitized and gridded. Intermediate depth maps were generated from the interva thickness encountered in the O59 we (DPA Part 2, Ref. # ). The veocity surveys for South Venture are iustrated in Tabe Tabe : South Venture Veocity Surveys We Year Checkshot Checkshot VSP VSP Acquired Avaiabe Type Avaiabe Type South Venture O Yes Vertica No NA Venture D23 99 Yes Vertica No NA Venture B3 98 Yes Vertica No NA Venture B Yes Vertica No NA Venture B Yes Vertica Yes Vertica Venture H Yes Vertica No NA West Venture C Yes Deviated We No NA Oympia A2 983 Yes Vertica No NA The South Venture structure has been penetrated by ony one we. Stacking veocity data from the 983 dataset was used in the same manner as at Venture, to suppement and constrain the appied veocity fied. This is a reasonabe approach at Venture given the we veocity data s area distribution, but greater opportunity for error exists in the South Venture depth conversion, due to the imited we contro : Petrophysics A detaied petrophysica evauation of the mutipe reservoir sands, hydropressured and overpressured, has been conducted on the South Venture O59 we. The interpretation methodoogy and parameters are incuded in Part Two of this document (DPA Part 2, Ref. # ). The resuts of this evauation are iustrated in Tabe Tabe : South Venture Reservoir Parameter Summary Sand Measured Depth Eevation Gross Net Average Average Average Unit Top Base Top Base Thickness Pay Porosity Sw Permeabiity* (m) (m) (m ss) (m ss) (m) (m) (%) (%) (md) a * not cacuated The methodoogies used in the anaysis of the O59 we reied heaviy on those estabished for simiar reservoirs of the Venture Fied. This was necessary because no cores were cut in the O59 we, and a sands Chapter 2: Geoogy, Geophysics and Petrophysics

8 256 Deveopment Pan Appication encountered in the we, are interpreted to be either gas bearing or tight. Due to the ack of core data, water sands, and formation water sampes in South Venture, petrophysica parameters derived in simiar reservoirs of the Venture Fied supported the interpretation. Zona average porosity ranges from seven to 5 percent in the O59 we. Porosity was cacuated from the raw density measurement using matrix density vaues determined from crosspots and ithoogic descriptions. Water saturation for vaues used in the estimation of gas in pace was cacuated using the Archie equation. Cementation and saturation exponents correspond to those used in simiar reservoirs of the Venture Fied. True formation resistivity was determined from the deep induction measurement. In the absence of formation water sampes, formation water resistivity was estimated from Venture Fied data and og data. The cacuation of net porous sand thickness was found to be quite sensitive to the porosity cutoff vaue. In genera, a porosity cutoff vaue of percent was used. Lower porosity cutoff vaues of six to seven percent were appied in ow porosity overpressured sands which had favourabe gas fowrates on dristem tests. The water saturation cutoff vaue used was percent Gas In Pace Gas in pace estimates for the South Venture Fied have been generated using deterministic and probabiistic methods. The probabiistic assessment of gas in pace was conducted in 995 (DPA Part 2, Ref. # ). The summation of mean vaues from the output expectation curves generated for the five hydropressured Project sands is.3 E9M3. Resuts of this probabiistic assessment for the each of the Project sands are shown in Tabe Tabe : South Venture Probabiistic Estimates of Gas In Pace, E9M3 Reservoir Sandstone P9 P5 P Mean a Project Tota A deterministic assessment of gas in pace was generated in 985. The methodoogy used to generate the maps and gas in pace estimates is described in Part Two of this document (DPA Part 2 Ref. # ). Deterministic gas in pace estimates for Project sands are shown in Tabe and represent unrisked voumes. Tabe : South Venture Deterministic Estimates of Gas In Pace, E9M3 Reservoir Sandstone Gas in Pace a Tota 2.8 Chapter 2: Geoogy, Geophysics and Petrophysics

9 Deveopment Pan Appication GLENELG FIELD Fied History The Geneg Fied was discovered in 983 (DPA Part 2, Ref. # through ). The discovery we, Geneg J48, encountered stacked, hydropressured, gas pay in a number of separate poos in the ower Logan Canyon Formation and throughout the Missisauga Formation. During dristem testing, gas fowed at rates of up to 849 E3M3/d. Three subsequent wes, one of which was whipped, were dried to deineate the accumuation. Figure iustrates the top B poo structure (near top Missisauga eve) at Geneg. 6 ' 6 5' ' GLENELG N ' GLENELG E58A 338 GLENELG E GLENELG J48 " GLENELG H ' 34.5 ESTIMATED FREE WATER LEVEL 346 METRES Km. 43 3'.5 Mi. 6 ' 6 5' Figure : Geneg Top Missisauga (Top B Poo) Depth Structure Map Contour Interva: 2 metres Structura Configuration The Geneg feature is a arge roover anticina structure bounded to the north and southeast by major istric norma fauts, and to the northeast, south and west by dip cosure. Internay, the roover anticine is partiay dissected by a number of esser norma fauts, some of which exhibit significant throws. The fied is at an average depth of 34 metres subsea and covers an area of some 25 square kiometres. Chapter 2: Geoogy, Geophysics and Petrophysics

10 258 Deveopment Pan Appication Geoogy The Geneg area is ocated toward the southernmost extension of sands of the Sabe Deta compex. Approximatey 55 metres of Missisauga Formation is present there. The Missisauga Formation contains a ower sand/shae ratio than in more northern wes. It exhibits significant thicknesses of shaedominated section between the interbedded sandstones and shaes more typica of the Missisauga Formation. The ower 3 metres of the Missisauga Formation at Geneg is composed of coarsey interayered sandstone and shae. Sandstone intervas approximatey 5 metres thick, dominated by sharpbased sandy channe fi successions, are interbedded with shaey intervas of simiar thickness. The channe sands exhibit variabe deveopment across the Geneg structure. The upper 25 metres of the Missisauga Formation is composed of stacked coarseningupward cyces of shae to sandstone, deposited by successive detaobe progradations into the area. These cyces are correatabe across the Geneg structure. The individua sands capping these cyces exhibit northsouth variation in thickness and og character; this is associated with variation in reservoir quaity (DPA Part 2, Ref. # , & ). Hydropressured gas has been encountered in a number of separate poos within the Logan Canyon and Missisauga formations. Three of the poos within the Missisauga Formation, B, C and F, are considered of sufficient size to be deveoped. The gas poos tend to be restricted to specific stratigraphic horizons within a singe structura bock. The C poo is an exception, being hydrodynamicay continuous across a faut separating the N49 and J48 wes, with gas reservoired in different stratigraphic eves in each structura bock. As a resut of different reservoir quaities on either side of this faut, the C accumuation is subdivided into two substituent poos, C and C2. This is iustrated in Figures (a), (b) & ; and presented in further detai in Part Two (DPA Part 2, Ref. # ). The B, C/C2 and F poos are a reservoired in sands which occur in the uppermost 25 metres of the Missisauga Formation. The distribution of the various reservoir sands in this stratigraphic interva are modeed as north to south tapering wedges. This mode combines the effects of a northery source for the sands with syndepositiona downward movement on the northern bounding growth faut; the atter acts to trap most of the reservoir quaity sand in the northern portion of the structure. According to this mode, reservoir thickness is at a maximum adjacent to the northern bounding faut, and thins systematicay southward to the southern boundaries of the fied. The B and C2 poos are reservoired in the same stratigraphic interva, namey in the uppermost sands of the Missisauga Formation. The C and F poos are reservoired in an oder stratigraphic unit (informay termed the Geneg Sand). Consequenty, these gas poos may be represented by two reservoir deveopment modes. Convoution of the appropriate reservoir deveopment mode with structure maps and gas/water contacts for each of the poos permits construction of net pay maps. Net pay maps are then used for gas in pace determination. Figure (ab) shows the structura configuration for the Geneg C/C2 and F poos; Figure (ac) are net pay maps for the Geneg B, C/C2, and F poos. Chapter 2: Geoogy, Geophysics and Petrophysics

11 Deveopment Pan Appication ' 6 5' ' GLENELG N ' C POOL GLENELG E58A 3494 GLENELG E GLENELG J48 C2 POOL " GLENELG H ' 43 3' ESTIMATED FREE WATER LEVEL 355 METRES.5 Km..5 Mi. 6 ' 6 5' Figure (a): Geneg C/C2 Poos, Depth Structure Map Contour Interva: metres Note: Change of mapping horizon between J48 and N49 faut bocks. Refer to text and structura crosssection (Figure ). Chapter 2: Geoogy, Geophysics and Petrophysics

12 26 Deveopment Pan Appication 6 ' 6 5' ESTIMATED FREE WATER LEVEL 3635 METRES 43 39' GLENELG N ' GLENELG E58A GLENELG E GLENELG J48 " GLENELG H ' NO RESERVOIR DEVELOPMENT IN THE SOUTHERN PORTION OF THE FAULT BLOCK See DPA Ref. # ' 6 '.5 Km..5 Mi. ESTIMATED FREE WATER LEVEL 3635 METRES 6 5' Figure (b): Geneg F Poo, Depth Structure Map Contour Interva: 2 metres Chapter 2: Geoogy, Geophysics and Petrophysics

13 Deveopment Pan Appication 26 6 ' 6 5' 5 5 ESTIMATED FREE WATER LEVEL 346 METRES ' GLENELG N ' GLENELG E58A GLENELG E58.6 GLENELG J48 " GLENELG H ' 43 3'.5 Km. 6 '.5 Mi. 6 5' Figure (a): Geneg B Poo, Net Pay Map Contour Interva: metre Chapter 2: Geoogy, Geophysics and Petrophysics

14 262 Deveopment Pan Appication 6 ' 6 5' ' C POOL GLENELG N ' ESTIMATED FREE WATER LEVEL 355 METRES GLENELG E58A GLENELG E GLENELG J48 C2 POOL 5 " GLENELG H ' 43 3'.5 Km..5 Mi. 6 ' 6 5' Figure (b): Geneg C/C2 Poo, Net Pay Map Contour Interva: Variabe, 2 Metres Note: Change of mapping horizon between J48 and N49 faut bocks. Refer to text and structura crosssection (Figure ). Chapter 2: Geoogy, Geophysics and Petrophysics

15 6 Deveopment Pan Appication ' 6 5' 43 39' GLENELG N ' 4 8 GLENELG E58A GLENELG E58 2 GLENELG J ESTIMATED FREE WATER LEVEL 3635 METRES 6 NO RESERVOIR DEVELOPMENT SEE REF. # " GLENELG H ' 43 3'.5 Km..5 Mi. 6 ' 6 5' Figure (c): Geneg F Poo, Net Pay Map Contour Interva: 2 metres Reservoir Zonation The presence of hydrodynamicay separate, stacked, gas accumuations in the Geneg Fied is indicated by pressure data and the intersection by the wes of severa discrete gas/water contacts. This necessitates division of the reservoir interva into a number of zones. Zone boundaries are taken at the base of shae intervas beieved, on the basis of pressure work, to be seas to gas migration. Each reservoir zone has, for the purpose of initia modeing of recoverabe gas reserves, been treated as a singe fow unit (DPA Part 2, Ref. # ). Figure iustrates a Geneg schematic structura crosssection. Chapter 2: Geoogy, Geophysics and Petrophysics

16 264 Deveopment Pan Appication E58 E58A N49 J48 H38 32 A B BASE NASKAPI MBR. LOGAN CANYON FM. TOP MISSISAUGA FORMATION 34 DECREASING RESERVOIR DEVELOPMENT FWL 346 B POOL NASKAPI MBR. BASE C POOL "GLENELG SAND" C2 POOL FWL 355 FWL F POOL FWL 3635 TOP NASKAPI MBR. LOGAN CANYON FM N49 42 N BASE NASKAPI MBR. TOP MISSISAUGA H38 E58A J48 E58 B A 44 metres km Figure : Geneg Schematic Structura Crosssection Chapter 2: Geoogy, Geophysics and Petrophysics

17 Deveopment Pan Appication : Geophysics : Seismic Database The depth structure map used for gas in pace estimates is based on a 3D seismic dataset covering 333 square kiometres (iustrated in Figure ) and was acquired in Acquisition and processing detais are iustrated in Tabe Seismic data quaity is good down to the objective eve Top Missisauga. 6 6 GLENELG SDL Figure seismic ine G G Geneg 3D Survey Outine Km. 2 Mi. N Figure : Geneg Seismic Database Map Chapter 2: Geoogy, Geophysics and Petrophysics

18 266 Deveopment Pan Appication Tabe : Geneg Acquisition and Processing Summary Data Survey Incorp. Acq. Acq. Proc. Fied Proc. Type Name In Study Date Stye Date Kms Detais Comments 3D 4E Yes Marine km2 4 Fod, Generay good data quaity Desig, FK Migration 2D 48E No 985 Marine Fod, Generay very good data quaity Desig, FK Migration 2D 33E Yes 982 Marine Fod, Generay poor to fair data quaity Desig, FD Migration 2D 2E Yes 98 Marine Fod, Generay poor data quaity Desig, FD Migration 2D 23E Yes 98 Marine Fod, Generay poor to fair data quaity Desig, FD Migration 2D 2E No 96 Marine Fod, Generay poor data quaity No Mig Time Interpretation Interpretation of the Geneg 3D seismic dataset commenced in 986 on a Landmark III TM workstation. Time structure maps for the Wyandot, Top Lower Logan Canyon, Naskapi, and Top Missisauga horizons were created, and are incuded in Part Two of this document (DPA Part 2, Ref. # ). The Top Missisauga Event, correated from we contro (Tabe ), was seected as the main mapping horizon and used to define this arge compex structure. In order to produce structure maps for the four main poos (B, C, C2 and F), it was assumed that sands within the Missisauga Formation (eg. the Geneg Sand) parae the Top Missisauga marker (DPA Part 2, Ref. # ). A representative seismic ine from the 3D survey is iustrated in Figure Chapter 2: Geoogy, Geophysics and Petrophysics

19 Deveopment Pan Appication 26 Tabe : Geneg Horizon Markers FIELD Geneg H38 J48 N49 E58 MAP HORIZON Depth Depth Depth TWT Depth Depth Depth TWT Depth Depth Depth TWT Depth Depth Depth TWT MD (m) TVD (m) (Mss) (sec) MD (m) TVD (m) (Mss) (sec) MD (m) TVD (m) (Mss) (sec) MD (m) TVD (m) (Mss) (sec) Wyandot Chak Top L.Logan Can Naskapi Missisauga Verri Canyon Jurassic S TD North Geneg N49 Geneg J48 South.5 Lower Logan Canyon 2. Naskapi 2.5 Missisauga 3. Figure : Geneg Seismic Section Depth Conversion Utiization of timedepth functions derived from we contro was found to be a more satisfactory method of depth conversion than reying on smoothed average stacking veocities. Time structure maps were generated and timedepth functions derived from the we contro were used to generate depth maps (DPA Part 2, Ref. # ). Chapter 2: Geoogy, Geophysics and Petrophysics

20 268 Deveopment Pan Appication Tabe : Geneg We Veocity Data We Year Checkshot Checkshot VSP VSP Acquired Avaiabe Type Avaiabe Type Geneg J Yes Vertica No NA Geneg E Yes Vertica Yes Vertica Geneg H Yes Vertica No NA Geneg N Yes Vertica Yes Vertica Petrophysics Petrophysica evauation of the four Geneg wes used a avaiabe og data, conventiona core anaysis data and pressure data. A detaied summary of the interpretation parameters and methodoogy is incuded in Part Two of this document (DPA Part 2, Ref. # ). Given the ack of specia core anayses on Geneg core, and the perceived simiarities between reservoirs in the Geneg and Ama fieds, Ama specia core anayses resuts were used for examination of the Geneg Fied. The resuts of this evauation are iustrated in Tabe Tabes : Geneg Reservoir Parameter Summary Geneg E58 K.B. 24 Metres Sand Measured Depth Eevation Gross Net Average Average Average Unit Top Base Top Base Thickness Pay Porosity Sw Permeabiity* (m) (m) (m ss) (m ss) (m) (m) (%) (%) (md) B C Geneg E58A K.B. 24 Metres Sand Measured Depth Eevation Gross Net Average Average Average Unit Top Base Top Base Thickness Pay Porosity Sw Permeabiity* (m) (m) (m ss) (m ss) (m) (m) (%) (%) (md) B C Geneg N49 K.B. 23 Metres Sand Measured Depth Eevation Gross Net Average Average Average Unit Top Base Top Base Thickness Pay Porosity Sw Permeabiity* (m) (m) (m ss) (m ss) (m) (m) (%) (%) (md) B C Geneg J48 K.B. 24 Metres Sand Measured Depth Eevation Gross Net Average Average Average Unit Top Base Top Base Thickness Pay Porosity Sw Permeabiity* (m) (m) (m ss) (m ss) (m) (m) (%) (%) (md) C F * Estimated from DSTs Chapter 2: Geoogy, Geophysics and Petrophysics

21 Deveopment Pan Appication 269 Average porosity ranges from 4 to 8 percent in the four major gas bearing zones. The primary contro on porosity is average grain size. Irreducibe water saturations, as cacuated from ogs, range from to 6 percent. Porosity was cacuated from density caibrated to stressed core porosity measurements. Water saturation vaues used in the estimation of gas in pace was cacuated using the Archie equation. Cementation and saturation exponent vaues were based on specia core anaysis from the Ama Fied. Formation water resistivity was derived from RFT and DST fuid sampe anaysis. A formation temperature gradient was determined from bottom hoe temperature measurements. Net pay cutoff criteria were based on core anaysis data. Net pay thickness was determined based on a permeabiity cutoff of. md to air at ambient conditions. This was found to correspond to an in situ porosity vaue of percent and a water saturation cutoff of percent Gas in Pace The ranges of uncertainty of the parameters utiized in the probabiistic assessment of gas in pace are detaied in Part Two (DPA Part 2, Ref # ). The resuts for the main poos in the Geneg Fied are presented in Tabe Deterministic gas in pace estimates, performed in 99 and 99, used average reservoir porosity and water saturation vaues determined from we petrophysics and average net pay vaues. The atter were determined from convoving the reservoir deveopment mode with what was then considered the most ikey structure maps for the area of the B, C/C2, and F poos. This information is presented in detai in Part Two (DPA Part 2 Refs. # and # ). The resuts are presented in Tabe The deterministic voumes are simiar to the P5 and Mean vaues obtained from the probabiistic method. Chapter 2: Geoogy, Geophysics and Petrophysics

22 2 Deveopment Pan Appication Tabe : Geneg Fied Probabiistic Estimates of Gas In Pace Reservoir Sandstone P9 P5 P Mean (E9M3) B C C F Project Tota Tabe : Geneg Fied Deterministic Estimates of Gas In Pace Reservoir Sandstone Gas in Pace (E9M3) B 6.3 C 3.9 C2.5 F. Project Tota.8 Chapter 2: Geoogy, Geophysics and Petrophysics

23 Deveopment Pan Appication ALMA FIELD Fied History The Ama Fied was discovered in 984 (DPA Part 2, Ref. # ). The discovery we, Ama F6, encountered stacked, hydropressured, gas pay in a number of separate poos in the uppermost 2 metres of the Missisauga Formation. During dristem testing, gas fowed at rates of up to 842 E3M3/d. Foowup driing consists of one we, Ama K85. This we encountered gas pay throughout the Missisauga Formation. A depth structure map for the top Missisauga Formation at Ama is shown in Figure ' 6 35' 43 38' 43 38' F ' K ESTIMATED FREE WATER LEVEL 296 METRES 43 35' 2 3 Km. 6 4' 2 Mi. 6 35' Figure : Ama Top Missisauga (Top A Poo), Depth Structure Map Contour Interva: 25 metres Chapter 2: Geoogy, Geophysics and Petrophysics

24 22 Deveopment Pan Appication Structura Configuration The Ama structure consists of a roover anticine bound to the north and south by major istric fauts. The cresta portion of the roover anticine is divided into two highs within which each of the wes were dried. It is compicated by a number of northeast/southwest striking norma (possiby growth) fauts with minor downtoeast throws. The fied ies at an average depth of 294 metres and covers an area of some 32 square kiometres. Separate structura maps have to be constructed for each reservoir zone because of atera and tempora variation in growth and sedimentation aong the northern bounding faut. Figure (ab) shows the structura configuration at the tops of the B and C Sands, respectivey. 6 4' 6 35' 43 38' 43 38' F ' K ' ESTIMATED FREE WATER LEVEL 298 METRES 2 3 Km. 6 4' 2 Mi. 6 35' Figure (a): Ama Top B Sand, Depth Structure Map Contour Interva: 25 metres Chapter 2: Geoogy, Geophysics and Petrophysics

25 3 Deveopment Pan Appication ' 6 35' 43 38' 43 38' F ' K ' ESTIMATED FREE WATER LEVEL 2999 METRES 2 3 Km. 6 4' 2 Mi. 6 35' Figure (b): Ama Top C Sand, Depth Structure Map Contour Interva: 25 metres Geoogy The Ama Fied is ocated near the southernmost extension of sands at the top of the Sabe Deta compex. The sandy reservoir section (Missisauga Formation) is approximatey 3 metres thick in this area. Hydropressured gas was encountered throughout the Missisauga Formation in the K85 we, and in the upper part of the formation in the F6 we. Five separate poos are recognized. Three of these, A, B, and C, have significant voumes of gas. The three main poos show simpe cosure to the east due to the punge of the roover anticine. Crossfaut sea is provided to the north by juxtaposition of the reservoir units with shaes of the Verri Canyon Formation, and to the south and west by their juxtaposition with Naskapi and ower Logan Canyon shaes. The Missisauga Formation at Ama is made up of a number of stacked coarseningupward shaetosandstone detaic cyces. Extensive coring has enabed sedimentoogica anaysis of the reservoir section, much of which is interpreted as detafringe sediments. These were deposited on the shef, severa kiometres seaward of the actua shoreine, in shaow waters affected by tida currents, as we as food and stormgenerated fows, which carried sit and sand offshore. The uppermost sand unit in Zone A is interpreted, on the Chapter 2: Geoogy, Geophysics and Petrophysics

26 24 Deveopment Pan Appication basis of sedimentary structures, as being deposited in a more tiday infuenced estuarine setting (DPA Part 2, Ref. # ). Changes in both thickness and sedimentoogy occur within the reservoir section between the two wes. The succession thins, and becomes ess sandrich in a southwestward direction. This is associated with a degradation in reservoir quaity (see Ama: Petrophysics). The reservoir deveopment mode used for gas in pace determination for the three poos at Ama is one of a north to south tapering wedge. This mode combines the effects of a northery source for the sands with syndepositiona downward movement on the northern bounding growth faut; the atter acts to trap most of the reservoir quaity sand in the northern portion of the structure. According to this mode, reservoir thickness is at a maximum adjacent to the northern bounding faut, and thins systematicay southward through the F6 and K85 wes, to the southern boundary of the fied. Accompanying this trend in reservoir thickness is a southward decrease in grain size, and hence porosity deveopment. Convoution of this reservoir deveopment mode with structure maps and gas/water contacts for each of the poos permits construction of net pay maps. Net pay maps are then used for gas in pace determination. Figure (ac) iustrates the variation in net pay distribution across the Ama structure in the three main poos. 6 4' 6 35' 43 38' 43 38' F ' 2 K ESTIMATED FREE WATER LEVEL 296 METRES 43 35' 2 3 Km. 6 4' 2 Mi. 6 35' Figure (a): Ama A Poo, Net Pay Map Contour Interva: 5 metres Chapter 2: Geoogy, Geophysics and Petrophysics

27 2 Deveopment Pan Appication ' 6 35' 43 38' 43 38' F ' 4 2 K ESTIMATED FREE WATER LEVEL 298 METRES 43 35' 2 3 Km. 6 4' 2 Mi. 6 35' Figure (b): Ama B Poo, Net Pay Map Contour Interva: 2 metres Chapter 2: Geoogy, Geophysics and Petrophysics

28 26 Deveopment Pan Appication 6 4' 6 35' 43 38' 43 38' 2 2 F ' 4 3 K ESTIMATED FREE WATER LEVEL 2999 METRES 43 35' 2 3 Km. 6 4' 2 Mi. 6 35' Figure (c): Ama C Poo, Net Pay Map Contour Interva: metre Log correatabiity and reservoir pressure anaysis indicate continuity of shaes and reservoir intervas between the two wes in the upper twothirds of the Missisauga Formation. Correation is more probematic in the ower 5 to metres of the Missisauga. This probaby indicates syndepositiona growth faut activity between the two wes, which has affected sand distribution patterns Reservoir Zonation The Ama reservoir section is divided into five zones in order to refect the presence of stacked, hydrodynamicay separate gas accumuations (DPA Part 2, Ref. # ). These separate gas poos are indicated by pressure data and the intersection by the wes of a number of discrete gas/water contacts. Their zone names correspond to the names of the associated gas poo. Zone boundaries are taken at the base of shae intervas beieved, on the basis of pressure work, to be seas to gas migration. Each reservoir zone has, for the purpose of initia modeing of recoverabe gas reserves, been treated as a singe fow unit (DPA Part 2, Ref. # ). Chapter 2: Geoogy, Geophysics and Petrophysics

29 Deveopment Pan Appication 2 A B K85 F6 CORE CORE NASKAPI MBR. LOGAN CANYON FM. A POOL 296 B POOL 298 TOP B ZONE TOP C ZONE C POOL 2999 TOP D ZONE B F6 K85 KILOMETERS 5 5 metres (subsea) A Figure : Ama Schematic Structura Crosssection Chapter 2: Geoogy, Geophysics and Petrophysics

30 28 Deveopment Pan Appication Geophysics Seismic Database The depth structure maps used to appraise reserves in Ama are based on a 2D seismic dataset consisting of ines acquired throughout the period This is iustrated in Figure Seismic data quaity is generay fair to good to the objective eve. A summary of acquisition and processing detais is given in Tabe " Figure seismic ine 434 ALMA SDL " 434 " " N Km Mi. Figure : Ama Seismic Database Map Chapter 2: Geoogy, Geophysics and Petrophysics

31 Deveopment Pan Appication 29 Tabe : Ama Acquisition and Processing Summary Data Survey Incorp. Acq. Acq. Proc. Fied Proc. Type Name In Study Date Stye Date Kms Detais Comments 2D 8624s648E No 985 Marine Fod, Generay good quaity data. Desig, FK Migration 2D 8624S643E Yes 984 Marine Fod, Generay fair to good Desig, data quaity. FD Migration 2D 8624S63E Yes 983 Marine Fod, Generay fair to good Desig, data quaity. FK Migration 2D 8624S63E Yes 983 Marine Fod, Generay fair to good Desig, data quaity. FD Migration 2D 8624S633E Yes 982 Marine Fod, Generay good data quaity. Desig, FD Migration 2D 8624S62E Yes 98 Marine Fod, Generay fair to good data. Desig, FD Migration 2D 8624S62E No 96 Marine Fod, Generay poor data quaity. No Mig Time Interpretation The 2D seismic data were interpreted manuay and time structure maps were made for the Wyandot, Base Sabe Shae, Naskapi, and Top Missisauga horizons. The Top Missisauga Event, correated from we contro (Tabe ), was used as the main mapping horizon. Ama contains three main sand units which thin in a dista direction. The A Sand is assumed to be conformabe to the Top Missisauga. However, the B and C Sand surfaces are not subparae to the Top Missisauga and so new structure maps were created for these sands by summing wedges equa to the isopach thicknesses for the we tops of Sands A to B and tops A to C, respectivey. This information is incude in Part Two (DPA Part 2, Ref. # ). Tabe : Ama Horizon Markers FIELD ALMA F6 K85 MAP HORIZON Depth Depth Depth TWT Depth Depth Depth TWT MD (m) TVD (m) (Mss) (sec) MD (m) TVD (m) (Mss) (sec) Wyandot Chak Top L. Logan Can Naskapi Missisauga Verri Canyon TD Chapter 2: Geoogy, Geophysics and Petrophysics

32 28 Deveopment Pan Appication North Ama F6 South.2.4 Base Sabe Shae.6.8 Naskapi Marker Top Missisauga Marker Figure : Ama Seismic Section Depth Conversion In a manner simiar to the depth conversion work at Geneg, a repacement veocity was used for the water ayer; and timedepth tabes, derived from the we contro, were used to produce depth maps from the respective horizon time structure maps as iustrated in Tabe (DPA Part 2, Ref. # ). Tabe : Ama We Veocity Data We Year Checkshot Checkshot VSP VSP Acquired Avaiabe Type Avaiabe Type Ama F6 984 Yes Vertica No NA Ama K Yes Vertica No NA Petrophysics A detaied petrophysica evauation of the two wes in the Ama reservoir has been conducted using a avaiabe wireine og data, conventiona and specia core anaysis data and pressure data. A detaied summary of the interpretation parameters and methodoogy is incuded in Part Two (DPA Part 2, Ref. # ). The resuts of this evauation are iustrated in Tabe Chapter 2: Geoogy, Geophysics and Petrophysics

33 Deveopment Pan Appication 28 Tabe : Ama Reservoir Parameter Summaries Ama F6 K.B. 2.4 Metres Sand Measured Depth Eevation Gross Net Average Average Average Unit Top Base Top Base Thickness Pay Porosity Sw Permeabiity* (m) (m) (m ss) (m ss) (m) (m) (%) (%) (md) A B C Ama K85 K.B. 24. Metres Sand Measured Depth Eevation Gross Net Average Average Average Unit Top Base Top Base Thickness Pay Porosity Sw Permeabiity* (m) (m) (m ss) (m ss) (m) (m) (%) (%) (md) A B C *Estimated from DSTs The buk of reserves in the Ama Fied are contained in three separate hydropressured reservoirs, with individua gas/water contacts. Average porosity ranges from 5 to 8 percent with the primary contro on porosity being average grain size. Irreducibe water saturations, as cacuated from ogs, range from to 6 percent. Porosity was cacuated from density ogs caibrated to stressed core porosity measurements. Water saturation vaues used in the estimation of gas in pace were cacuated using the Archie equation. Cementation and saturation exponent vaues were based on specia core anaysis stressed formation resistivity factor and resistivity index measurements. Formation water resistivity was derived from RFT and DST fuid sampe anaysis. A formation temperature gradient was determined from bottom hoe temperature measurements. Net pay cutoff criteria were based on core anaysis data. Net pay thickness was determined based on a permeabiity cutoff of. md to air at ambient conditions. This was found to correspond to an in situ porosity vaue of percent and a water saturation cutoff of 6 percent Gas in Pace The ranges of uncertainty of the parameters utiized in the probabiistic assessment of gas in pace are detaied in Part Two (DPA Part 2, Ref # ). The resuts for the three main poos in the Ama Fied are presented in Tabe Deterministic gas in pace estimates were performed in 99 and 99. Average reservoir porosity and water saturation vaues were determined from we petrophysics and average net pay vaues. These were determined from the net pay maps, and what was then considered the most ikey structure maps for the area of the three poos. The methodoogy of this deterministic gas in pace determination is presented in detai in Part Two (DPA Part 2, Refs. # and # ); the resuts are presented in Tabe The deterministic voumes are simiar to the P5 and Mean vaues obtained from the probabiistic method. Chapter 2: Geoogy, Geophysics and Petrophysics

34 282 Deveopment Pan Appication Tabe : Ama Probabiistic Estimates of Gas In Pace, E9M3 Reservoir Sandstone P9 P5 P Mean A B C Project Tota Tabe : Ama Deterministic Estimates of Gas In Pace, E9M3 Reservoir Sandstone Gas in Pace A.3 B 3.4 C.4 Project Tota 5. Two other poos, D and E, were encountered deeper in the K85 we. Correative sands in the F6 we are wet, indicating either imited gas coumns, sand pinchout, or the presence of a seaing faut between the wes. Current interpretation indicates that the reserves contained in these deeper sands in K85 are too sma to warrant incusion in the Sabe Offshore Energy Project deveopment. Chapter 2: Geoogy, Geophysics and Petrophysics