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Home My WebLink About2010 Oooguruk UnitPIONEER NATURAL RESOURCES ALASKA April 2, 2012 Commissioner Cathy Foerster Alaska Oil and Gas Conservation Commission 333 W. 7th Ave., Suite 100 Anchorage, AK 99501 Dale Hoffman, CPL Senior Staff Landman Pioneer Natural Resources Alaska, Inc. 700 G Street, Suite 600 Anchorage, AK 99501 (907) 343-2108 • Fax (907) 343-2193 dale.hoffman@pxd.com RECEIVED APR o 2 2012 Alaska Oil & GIs Cees. Cammisiun Andwrage Annual Reservoir Surveillance Reports — Oooguruk Unit Oooguruk-Kuparuk, Oooguruk-Nuigsut & Oooguruk-Torok Oil Pools Dear Commissioner Foerster: The Alaska Oil and Gas Conservation Commission (AOGCC) approved pool rules for the Oooguruk-Kuparuk, Oooguruk-Nuiqsut and Oooguruk-Torok pools within the Oooguruk Unit as Conservation Orders 596, 597 and 645, respectively. Rule 9 of the orders requires the filing of annual surveillance reports, which are attached hereto. Please let us know if you have any questions or require additional information regarding these reports. Sincerely, Attachments PIONEER NATURAL RESOURCES ALASKA RECEIVED APR 0 2 2012 Alaska Oil & Gas Cons. Commission Anchorage Annual Reservoir Surveillance Report Oooguruk-Kuparuk Oil Pool Oooguruk Field April 1, 2012 Table of Contents SUBTECT PAGE 1.0 Progress of the Enhanced Recovery Project.............................................................. 1 2.0 Results and Analysis of Reservoir Pressure Surveys Within the Pool .....................1 3.0 Results and Analysis of Production and Injection Log Surveys, Tracer Surveys, Observation Well Surveys and Any Other Special Monitoring..................................1 4.0 Review of Pool Production Allocation Factors and Issues Over the Year ................ 2 5.0 Reservoir Management Summary................................................................................2 Attachments A. Voidage Balance by Month of Produced Fluid and Injected Fluids 2011 B. Map of Kuparuk Well Locations C. Form 10-412 Pressure Report for Kuparuk D. Kuparuk Reservoir Pressure Map — July 2011 Annual Reservoir Surveillance Report Oooguruk-Kuparuk Oil Pool Pioneer Natural Resources Alaska, Inc. Oooguruk Development Project 1.0 Progress of the Enhanced Recovery Project During 2011, activities within the Kuparuk Pool were extended to two additional fault blocks. One well (ODSK-13) was drilled in the Oooguruk-Kuparuk Oil Pool within the Ivik Fault Block, and is currently shut-in pending stimulation treatment. One well (ODSN40) had rig workover operation, converting the well to injection within the Colville Delta fault block. The ODSK-14, ODSK-33 and ODSK-41 wells continued to produce throughout 2011. Water breakthrough occurred in ODSK-35i prior to conversion to injection. The ODSK-38i well continued on injection throughout the year and ODSK-35i was converted to injection late in the year, after period of pre -production. Both injectors are performing as expected in replacing off take, as of December 2011. Injection well ODSK-42i was active for part of the year. The ODSK 42i well could not maintain consistent injection at the water injection header pressure post gel treatment in 2010. The locations of these wells are shown on Attachment B. Average daily Kuparuk production for 2011 was 3,578 BOPD. Cumulative oil production from the Oooguruk-Kuparuk Oil Pool during 2011 was 1,306 MBO and 6,919 MBO since field start- up. No additional drilling for the pool is planned for 2012. Average daily Kuparuk water injection for 2011 was 6,149 BWPD. Cumulative water injection in the Oooguruk-Kuparuk Oil Pool during 2011 was 2,244 MBW and 7,966 MBW since the start of the project. 2.0 Results and Analysis of Reservoir Pressure Surveys within the Pool Pressure build up tests were completed in ODSK-33, ODSK-35 and ODSK 41 during 2011, the results of which are presented in Attachment C. In addition, pressure fall off tests were performed on ODSK-38i and ODSK-42i during the year. The pressure build up in ODSK-33, ODSK-41, AND ODSK-35 indicate reservoir pressure was being drawn down around the wellbores compared to original static pressure. Water injection support is evident in the ODSK-33 pressure and production results. ODSK-41 is still not seeing much support from injection in ODSK-38i. The pressure fall off in ODSK-38i indicates elevated pressures around this wellbore due to extensive water injection. The pressure in ODSK-42i indicates pressure drawdown in this area of the reservoir as the well has been shut in from injection since the gel squeeze to shut off thief zones. 3.0 Results and Analysis of Production and Injection Log Surveys, Tracer Surveys, Observation Well Surveys and any Other Special Monitoring No special logging or monitoring program was initiated. Page 1 of 7 4.0 Review of Pool Production Allocation Factors and Issues Over the Year Production from the Oooguruk-Kuparuk and Oooguruk-Nuiqsut pools is commingled at the surface into a common production line. Allocation between the pools is based on ratio of total production for a pool to the total production for the Oooguruk Unit. The pool allocation factors for 2011 are: Oooguruk-Kuparuk Pool: 50.3% Oooguruk-Torok Pool: 6.6% Oooguruk-Nuiqsut Pool: 43.1% Theoretical production for individual wells for both pools is calculated on a daily basis. During 2011 wells were produced with chokes at 100% the most of the time due to the capacity of the production line. Daily theoretical production for a well was calculated using the data from the most current well test and the amount of time a well was on production for a given day: Minutes produced 1440Minute e xDailyRate(BOPD)we11,s,=TheoreticalDailyProduction ay The daily allocation factor for the unit is calculated by dividing the actual total production for the day by the sum of the theoretical daily production for each individual well. Daily allocated production is assigned to each well by multiplying its theoretical daily production by the daily allocation factor. The average daily allocation factor for 2011 was 0.92. 5.0 Reservoir Management Summary The Alaska Oil and Gas Conservation Commission (AOGCC) issued pool rules under Conservation Orders No. 645, 596 and 597 for the Oooguruk-Torok, Oooguruk-Kuparuk and Oooguruk-Nuiqsut reservoirs, respectively. Subsurface development of the Oooguruk Unit is done with dedicated development wells to the Oooguruk-Torok, Oooguruk Nuiqsut and Oooguruk-Kuparuk oil pools with no subsurface commingling. Unitized substances produced from the Oooguruk-Torok , Oooguruk-Nuiqsut and the Oooguruk Kuparuk oil pools are commingled on the surface. Area injection orders authorizing the injection of fluids for enhanced oil recovery in the Oooguruk-Kuparuk and Oooguruk Nuiqsut reservoirs were issued by the AOGCC as Area Injection Orders No. 33 and 34, respectively. Pioneer commenced injection into both reservoirs in 2009. As of January 2012, there are four active producing and three active injecting Kuparuk wells. Kuparuk production has exceeded expectations from ODSK-33, ODSK-41 and ODSK-14 due to possible non -matrix flow into these wells. Kuparuk injection commenced in 2009, into ODSK- 38i with excellent injection rates. Kuparuk injection commenced in 2011 into ODSK-35i and ODSN-40 (converted from Nuiqsut completion to Kuparuk completion). Injection rate into ODSK-35i is very good, with rate into ODSN-40 good, considering the pay thickness at that location. Page 2 of 7 The better than expected neater injection rate has arrested the gas/ oil ratio (GUK) increase in the ODSK-33 and has stabilized the flowing bottom hole pressure. The ODSK-33 experienced water breakthrough in August 2010. This was approximately the timing that reservoir simulation had suggested for breakthrough. The water cut increased relatively rapidly and reached approximately 82% by the end of, 2011. ODSK-41 is much further away from injection and has not yet seen a dramatic response to water injection in ODSK-38i. Injection logging confirmed that water injection in the K -38i well was limited to the perforated Kuparuk section. Injection was initiated in ODSK-42Ai in January 2010. Unfortunately, this resulted in a very early water breakthrough event in the ODSK 41 well. The ODSK-42Ai was shut in and the water injection rate quickly decreased from the producing well. It is possible a fracture system connects the two wells together. This was not unexpected based on the high productivity from the ODSK-41 wells originally. In 2010, ODSK-42i was squeezed with a combination of gels to attempt to seal up the fracture connection. Those are polyacrylamide gels that set up to a "ringing gel" at reservoir conditions. The ODSK-42Ai was placed back on injection and was injecting just under 1,000 BWPD for about 30 days. Then, after an upset event from the Kuparuk River Unit Seawater Treatment Plant, continuous injection could not be sustained. Some solid materials may have caused some near wellbore plugging. ODSK-35 and ODSK-14 were both drilled during 2010. The total thickness of the Kuparuk was less than expected in these wells to the north and northwest of the ODSK-33. The wells had very high initial productivity from good reservoir quality, but have declined due to the thinner nature of the reservoir. ODSK-35i was converted to injection in late, 2011. With ODSK-35i and ODSK-38i both injecting, reservoir voidage replacement is maintained, pressure in the reservoir is increasing, and GORs are decreasing. ODSK-13 was drilled in late 2011 as horizontal producer completed to test the thickness and productivity of the Ivik fault block. Unfortunately, the well currently is awaiting stimulation treatment prior to production. ODSN-40, a Nuiqsut horizontal completion, had rig workover in 2011 to convert to dedicated Kuparuk injection. This well was completed and is injecting into the Kuparuk formation within the Colville -Delta fault block in an attempt to aid with pressure support and oil recovery into the ODSK-33 producer within the Kalubik fault block. Page 3 of 7 ATTACHMENT A Voidage Balance by Month of Produced Fluids and Injected Fluids 2011 Page 4 of 7 Net Injection (Injection - Production) Produced Fluids Cum Net Year since Injection, Cum, start-up, Total Year Cum since Total Year Water, Voidage, Cum, start-up, Month Oil, MRP Free Gas, MRS MRS MRS MRS MRS Cum Since Start -Up MRS -926 -1879 -95 -1021 23253 Jan -11 141 34 76 251 251 23504 Feb -11 147 31 85 263 515 24019 Mar -11 141 32 64 237 752 24770 Apr -11 183 66 129 377 1129 25900 May -11 184 86 106 376 1505 27405 Jun -11 156 86 113 355 1861 29265 Jul -11 143 88 136 367 2227 31493 Aug -11 112 68 128 308 2535 34028 Sep -11 122 51 147 320 2855 36883 Oct -11 115 49 161 325 3181 40064 Now11 96 44 159 299 3480 43543 Dec -11 93 28 167 288 3767 47311 2011 Totals 1633 664 1471 3767 Page 4 of 7 Net Injection (Injection - Production) Injected Fluids Cum Net Year since Injection, Cum, start-up, Cum Formation Import Total Year since Gas, Gas, Water. Injection, Cum, start-up, MRS MRS MRB MRS MRS MRS -926 -1879 -95 -1021 -1974 2546 0 -2271 0 193 193 193 2739 0 -2432 0 52 52 245 2791 0 -2486 0 142 142 387 2933 0 0 61: 61 448 2994 0 0 131 131 579 3125 0 0 261 261 840 3386 0 0 70 70 910 3456 0 0 242 242 1151 3697 0 0 225 225 1376 3922 0 0 277 277 1654 4200 0 0 293 293 1946 4492 0 0 321 321 2267 4813 0 0 2267 2267 Page 4 of 7 Net Injection (Injection - Production) Cum Net Year since Injection, Cum, start-up, MRS MRS MRS -953 -58 -58 -1011 -211 -270 -1223 -95 -365 -1318 -315 -681 -1634 -245 -926 -1879 -95 -1021 -1974 -297 -1318 -2271 -66 -1384 -2337 -95 -1479 -2432 -48 -1527 -2480 -7 -1533 -2486 33 -1501 -2454 -1501 ATTACHMENT B Map of Kuparuk Well Locations Page 5 of 7 89956 NADL389955t,s ADL379301 ADL30 AjDL389959 r- ADL389 8 a ODSK-13 ADL389954 ADL3893 — � OD •�_ O 5 35 —14 .4 D ` A.'M38pe ADL3�949 i ADL355337 +-� A L3 6 A L3�52 ADL3 51 SOD �r /t// rt � i y � I I 4 Legend ADL355039ADL Ku pa ru k PA °d 8 j Unit Boundary i WE Lease Boundary s Township Boundary Miles 0 1 2 4 Page 5 of 7 ATTACHMENT C Form 10412 Pressure Report for Kuparuk Pape 6 of 7 STATE OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION RESERVOIR PRESSURE REPORT 1. Operator: Pknnear Natural. Resources Alaska 2. Address: 700 G Street, S lle 800, Anchorage, AK 99501 3. Unit or Lease Name: Oooguruk 4. Field and Pool. 5. Datum Reference: Ooogmuk-Kuparuk 6050 6. Of Gravely: 25 7. Gas Grayly: 0.7 8. 4Nsll Name and hlurrbar. 5OXXX)000OOLXXX 9. AFI Number 10. type Sae NO DASHM instNeti0ns 11. AOGCC Poor Oode 12. Zone 13. Perforated 14. Final Teat 15. Shut -In 16. Press. 17. an 18. Depth Intervals Date Tms, Hours Surv. Type Terrp. TooINDSS Top - Bottom (see D6 TVs hatructbrns forcodes) 19. Rnal Observed Pressure at Tool Depth 20. Datum TVDSS pnput) 21. Pressure Gradient, psNR. 22. Pressure at Dolum(cap ODSK-33 50703205620000 O 576100 Kuparuk 5990-SD43 9!23!1' 135 PBU 166 5946 2085 6050 0.39 2,128 0DSK-35 507113205600100 O 578100 Kuparuk 6039-8057 WWW' 135 PBU 158 5793 1480 6050 0.39 11580 ODSK-41 50703205850000 O 576100 Kuparuk 5980-6034 WWI 1135 PBU 157 5653 921 6050 0.39 1,078 ODSK 38 50709205840000 WI 576100 Kuparuk 5850- 5981 9!4111 95 PFO 118 5840 3413 6050 0.44 3,505 0DSK-42 50703206050190 NA 576100 Kuparuk 5954-5970 916x11 131 PFO 141 5625 2909 1 9050 0.39 2,975 'Recorded raaervok pressure prior to flow ing back wof 23. Al tests reported herein w are made i1 accordance wkh the applicable rules, regulations and instructions of the Alealo3 OII and lyras Conservation Comrisapn. I hereby certify that the foregoing is two and correct to the beat of my In= ledge, Signature Title Prided Nrma Date Pape 6 of 7 "MOOF rx SOWWOF m r__ O'l :4,JW k ! ATTACHMENT D Kuparuk Reservoir Pressure Map — August 2011 ATTACHMENT D Kuparuk Reservoir Pressure Map —August 2011 �: 4 L71 NAU2TIAUk,La =no 4 (IEPSG2lY)4 'IMPAWN0.4 WMAW clatum is" womhowid NkluFM ariqkc ILM 00 COW, 544M Ovid] 61 AFIffA ATAYr PL &4&'jnCM Page 7 of 7 ti N Is ;,.P6, August 2011 Kuparuk Re servor Press -ore 47a:," WF h PIONEER NATURAL RESOURCES ALASKA RECEIVED APR 0 2 Z01Z Alaska Oil & Ges Cons. Commis8ier! Anchorage Annual Reservoir Surveillance Report Oooguruk-Nuigsut Oil Pool Oooguruk Field April 1, 2012 Table of Contents SUSTECT PAGE 1.0 Progress of the Enhanced Recovery Project..............................................................1 2.0 Results and Analysis of Reservoir Pressure Surveys within the Pool......................1 3.0 Results and Analysis of Production and Injection Log Surveys, Tracer Surveys, Observation Well Surveys and any Other Special Monitoring ........ 1 4.0 Review of Pool Production Allocation Factors and Issues over the Year.................2 5.0 Reservoir Management Summary................................................................................2 Attachments A. Voidage Balance by Month of Produced Fluid and Injected Fluids 2011 B. Map of Nuiqsut Well Locations C. Form 10-412 Pressure Report for Nuiqsut D. Nuiqsut Reservoir Pressure Maps July 2011 Annual Reservoir Surveillance Report Oooguruk-Nuiqsut Oil Pool Pioneer Natural Resources Alaska, Inc. Oooguruk Development Project 1.0 Progress of the Enhanced Recovery Project During 2011, two injection wells (ODSN-23i, ODSN 26i) were drilled and pre -produced. One injection well (ODSN-15i) was converted to water injection before year end after a period of pre -production, beginning the first water -flood pattern within the Colville - Delta fault block. ODSN-31, ODSN 37 and ODSN-36 continued to produce throughout 2011. They are supported by water and gas injection in ODSN-32i and ODSN-34i. As part of planned under -saturated water -alternating -gas (USWAG) process, gas injection has continued in ODSN-32i throughout most of the year. At year end, gas injection has also been initiated into ODSN-15i. The locations of all Nuiqsut wells are shown on Attachment B. Average daily Nuiqsut production during 2011 was 3,061 BOPD. Cumulative oil production from the Oooguruk-Nuiqsut Oil Pool during 2011 was 1,117 MBO and is 2,580 MBO since field start-up. During 2011, water and gas injection continued in the Oooguruk-Nuiqsut oil pool. Offset producing wells within the Kalubik Fault Block (ODSN-31, ODSN-36 and ODSN- 37) have seen gas/ oil ration (GOR) stabilization and arrest of production decline. Average daily Nuiqsut injection during 2011 was 2,279 BWPL7 and 2,113 Mscfd. Cumulative water injection in the Oooguruk-Nuiqsut Oil Pool during 2011 was 832 MBW and 1,595 MBW since the start of the project. Cumulative gas injection in the Oooguruk-Nuiqsut Oil Pool during 2011 was 771 MMscf and 1,101 MMscf since the start of the project. 2.0 Results and Analysis of Reservoir Pressure Surveys Within the Pool An initial static pressure test was completed on the three new Nuiqsut wells. Additionally, various pressure build-up or static tests were completed on the Nuiqsut wells in 2011. These pressures are reported in the attached 10-412 pressure form. The pressure build up tests indicate that pressure is being drawn down around the production well locations and is high around the injection wells. Waterflood injection began in 2009 in the ODSN-32i and ODSN-34i. GOR reduction and production decline stabilization have been observed in the offset producing wells.within the Kalubik fault block. The pressure surveys confirm that the Nuiqsut reservoir is low permeability evidenced by the high pressures at the injectors and low pressures at the producers. 3.0 Results and Analysis of Production and Injection Log Surveys, Tracer Surveys, Observation Well Surveys and any Other Special Monitoring In three Nuiqsut wells surveillance equipment was placed in the production liner to assess oil and water production conformance along the lateral via target fluid tracers which were monitored and analyzed by collecting surface fluid samples over time. Page 1 of 7 Annual Reservoir Surveillance Report Pioneer Natural Resources Alaska, Inc. Oooguruk-Nuigsut Oil Pool Oooguruk Development Project Initial data indicate adequate tracer concentrations are being returned in the produced fluids. A quantitative analysis is in progress. 4.0 Review of Pool Production Allocation Factors and Issues Over the Year Production from the Oooguruk-Kuparuk and Oooguruk-Nuiqsut pools is commingled at the surface into a common production line. Allocation between the pools is based on ratio of total production for a pool to the total production for the Oooguruk Unit. The pool allocation factors for 2011 are: Oooguruk-Kuparuk Pool: 50.3% Oooguruk-Torok Pool: 6.6% Oooguruk-Nuiqsut Pool: 43.1% Theoretical production for individual wells for both pools is calculated on a daily basis. During 2011 wells were produced with chokes at 100% the vast majority of the time due to the capacity of the production line. Daily theoretical production for a well was calculated using the data from the most current well test and the amount of time a well was on production for a given day: MlY1ZlteSproduced 1440 Minutesa xDailyRate(BOPD) s�errresr = TheoreticalDaily Pr oduction y The daily allocation factor for the unit is calculated by dividing the actual total production for the day by the sum of the theoretical daily production for each individual well. Daily allocated production is assigned to each well by multiplying its theoretical daily production by the daily allocation factor. The average daily allocation factor for 2011 was 0.92. 5.0 Reservoir Management Summary The Alaska Oil and Gas Conservation Commission (AOGCC) issued pool rules under Conservation Orders No. 645, 596 and 597 for the Oooguruk-Torok, Oooguruk-Kuparuk and Oooguruk-Nuigsut reservoirs, respectively. Subsurface development of the Oooguruk Unit is done with dedicated development wells to the Oooguruk-Torok, Oooguruk-Nuiqsut and Oooguruk-Kuparuk oil pools with no subsurface commingling. Unitized substances produced from the three oil pools are commingled on the surface. Area injection orders authorizing the injection of fluids for enhanced oil recovery in the Oooguruk-Kuparuk and Oooguruk-Nuigsut reservoirs were issued by the AOGCC as Area Injection Orders No. 33 and 34, respectively. Pioneer commenced injection into both reservoirs in 2009. As of January 2012 there are six producing wells and five injection wells, two of which are currently pre -producing in the Oooguruk-Nuiqsut oil pool. Currently, eight of those wells are active production wells and three are active injection wells. Page 2 of 7 Annual Reservoir Surveillance Report Oooguruk-Nuiqsut Off Pool Pioneer Natural Resources Alaska, Inc. Oooguruk Development Project The ODSN-15i was converted to injection in 2011. During 2011, ODSN-40 had a rig workover that installed injection liner equipment for dedicated Kuparuk injection. Water injection supply has been variable from the Kuparuk River Unit supply system. This has hampered efforts to maximize water injection during 2011. The focus for 2012 will be to maximize water and gas injection and to monitor for pressure and rate response in the offset production wells. ODSN-32i and ODSN-34i both had high pressure breakdown stimulation treatments for enhanced injection rate. Page 3 of 7 ATTACHMENT A 19 ■ Produced Fluids Y>I oduced Fluids and Injected Fluids 2x11 Injected Fluids Year Cum since Total Total Year Cum since Water. Injection, Cum, Water, Voidage, Cum, start-up, Month Dil, MRS Free Gas, MRS MRS MRS MRS MRS Cum Since Start -Up 1236 0 0 61 61 1823 Jan -11 109 15 0 124 124 1355 Feb -11 123 15 0 139 263 2086 Mar -11 117 29 1 147 410 2233 Apr -11 106 24 0 130 540 2363 May -11 101 12 2 115 655 2478 Jun -11 98 15 1 114 769 2592 Jul -11 97 17 0 114 884 2706 Aug -11 95 12 0 108 992 2815 Sep -11 113 11 1 126 1117 2940 Oct -11 97 14 1 111 1229 3052 Nov -11 92 12 2 106 1334 3157 Deo -11 126 67 1 194 1528 3351 2011 Totals 1274 244 10 1528 Y>I oduced Fluids and Injected Fluids 2x11 Injected Fluids Page 4 of 7 Net Injection (Injection - Production) Net • Year Cum since Total Year Cum since oration Import Gas, Water. Injection, Cum, start-up, Gas, MRS MRS MRS MRS MRS MRS -731 -47 -192 -778 -86 1236 0 0 61 61 61 129 0 0 58 58 119 1355 0 0 100 100 219 1455 31 0 13 44 263 1499 55 0 15 70 333 1569 80 0 15 95 428 1665 43 0 103 146 575 1811 6 0 127 133 706 1944 67 0 102 169 877 2113 99 0 88 187 1064 2300 69 0 81 150 1213 2449 89 0 78 167 1380 2616 540 0 840 1380 Page 4 of 7 Net Injection (Injection - Production) Net • Year Cum since Injection, Cum, start-up, MRS MRS MRS -587 -63 -63 -650 -81 -144 -731 -47 -192 -778 -86 -277 -864 -45 -322 -909 -19 -341 -928 32 -309 -896 25 -284 -870 43 -241 -827 75 -165 -752 44 -121 -708 -27 -1148 -735 -148: ATTACHMENT B Map of Nuiqsut Well Locations Page 5 of 7 i r1CL3899ao ti nGL39995� •. _� ^-.. i k k t AN ADL389960 3� AC_3$9959+ .y C�O� A�L38£95) ADL339949 31 , -89957 ADL339951 Legend ADL355039 } '�,^" ^• Nuigsut PA i AZUL 35.08 �'`=•., N `4Unit Boundary i U1E Lease Boundary I i Township Boundarym" 0 r �Miles 0 0.5 1 2 4 `� Page 5 of 7 ATTACHMENT C Form 10412 Pressiure Report for Nuicisut Page 6 of 7 STATE: OF ALASKA ALASKA OIL AND GAS CONSERVATION COMMISSION RESERVOIR PRESSURE REPORT 1. Operator: Pioneer Natural Resources Alaska 2. Address: 700 G Street, Suite 600, Anchorage, AK 99501 3. Unit or Lease Name: Oooguruk 4. Feld and Poot 5. Datum Reference: ocoguruk-WIgsut 6350 B. ON Gravity: 20 7. Gas Gravity: 0.7 S. Wel Name and Number: S. AFI Number 50)000000OOSX OO NO RASHES %Type See tnstructions 11. AOGCC Pool Code 12. Zone 13. Perforated 14. Final Test 15. Shut -n16. Press. 17. B.H. 18. Depth Mle Time, ervals Dame, Hours 5urv.Type Terp. ToolTVDSS Top- Bottom (see TVDSS instructions for codes) 19. Final Observed Pressure at Tool Depth 20. Datum TVDSS(input) 21. Pressure Gradient,psilft. 22. Pressure at Datum(cal) ODSM-18 50703206240000 O 576150 Nuiqsut 8207-6232 1110!11 Initial SBHP 168.9 6,160 3253 6350 0.40 3,329 OOSN-23 50703208390000 O 576150 1 Nuiqsut 6178-6555 7725111 Initial SBHP 147 5,594 1 2885 6350 0.40 3,187 ODS14-16 50703296200000 0 576150 Nuiqsut 6192-6235 8723!11 135 PBU 173 6,049 1923 6350 DAD 2,043 ODS14-17 50703206220000 O 576150 Nuiqsut 6122-6305 872372011 135 PBU 173 6,054 2038 5350 DAD 2,152 ODSM31 50703205650000 O 576150 Nuigsut 6074-6263 6!2372011 135 PBU 164 5,762 1387 8350 0.40 1,622 ODSM23 I 56703205390000 0 576150 Nuiqsut 8181-6221 872572011 135 PBU 1 151 5,577 2259 6360 0.46 2,568 ODSN-32 50703205660000 WAG 576150 Nuiqsut 5161-6314 8128111 237 PFO 138 5,969 4564 6350 0.44 4,732 ODSN-15 50703206180000 WAG 576150 Nuigstd 6170-6210 916/2011 456 PFO 135 5,416 2899 635D 0.40 3,273 ODSN-40 50703205710000 WAG 576150 Nuiqsut 6100-6337 916111 131 PFO 119 5,857 4451 6350 0.40 3,230 ODSN-28 1 50703208420000 O 576150 Nuiqsut 6056-6226 11129!11 Initial SBHP 164 5,922 3294 6350 0.40 3,465 23. All tests reported herein were nude In accordance with the applicable rules, reguIgo ns and instructions of the Alaska Oil and Gas Conseryation ComdssIon . I hereby certify that the foregoing is true and correct to the best of my know lodge. Signature Printed Name Date Page 6 of 7 10414WO zVwVV ATTACHMENT D IN uxqsutKeSerVO1r Irressure map — August LUI I ATTACHMENT D Nutqsut Reservoir Pressure Map — August 2011 X0 'It A Pioneer Natural Resources Alaska August 2011. Nulqsut Reservoir Pressure KIUMTM Tranmrie YMmlur curks Tm *OWSMA WAMI "A; VSO 00 COW. $4 W DOM --ALARK& KWO PlAWE TAW d Page 7 of 7 U,t.,r,t , V1140ON PIONEER NATURAL RESOURCES ALASKA RECEIVED APR 0 2 2012 Alaska Oil & Gas Cans. Comm issiOP Anchoraue Annual Reservoir Surveillance Report Oooguruk-Torok Oil Pool Oooguruk Field April 1, 2012 Table of Contents SUBTECT PAGE 1.0 Progress of the Enhanced Recovery Project.............................................................. 1 2.0 Results and Analysis of Reservoir Pressure Surveys Within the Pool .....................1 3.0 Results and Analysis of Production and Injection Log Surveys, Tracer Surveys, Observation Well Surveys and Any Other Special Monitoring..................................1 4.0 Review of Pool Production Allocation Factors and Issues Over the Year................2 5.0 Reservoir Management Summary................................................................................ 2 Attachments A. Map of Torok Well Locations B. Voidege Balance by Month of Produced Fluid and Injected Fluids 2011 C. Form 10-412 Pressure Report for Torok D. Torok Reservoir Pressure Map — August 2011 Annual Reservoir Surveillance Report Pioneer Natural Resources Alaska, Inc. Oooguruk-Torok Oil Pool Oooguruk Development Project 1.0 Progress of the Enhanced Recovery Project During 2011, one well, ODST-46 was drilled, completed and hydraulically fracture stimulated in the Oooguruk-Torok Oil Pool (OTOP). A second well, ODST-39, was drilled in 2011, completed in January 2012, and is awaiting hydraulic fracture stimulation. Sustained production from ODST-46 was initiated in May of 2011 with plans to convert the well to injection for enhanced recovery once production is established from ODST-39 and an Area Injection Order has been issued. An application for an Area Injection Order will be submitted in April 2012, with the intent to begin injection for enhanced recovery later the same year. The locations of the existing OTOP wells are shown on Attachment A. Average daily Torok production for 2011 was 467 BOPD. Cumulative oil production from the OTOP during 2011 was 170 MBO and is 306 MBO since field start-up thru 2011. No water or gas was injected into the OTOP during 2011. Attachment B details the 2011 monthly voidage for the OTOP. 2.0 Results and Analysis of Reservoir Pressure Surveys within the Pool An initial pressure of 2,397 psig (-5,000 '1'VDSS) was measured in the ODST-46 well on March 24, 2011 prior to fracture stimulating the well on March 28, 2011. A review of the data indicates the pressure was declining at approximately 10 psi per day following the end of the drilling and rig completion operations on March 20, 2011. Subsequently, ODST-46 was shut-in following the initial fracture stimulation and flowback on April 2, 2011 providing a stable initial pressure build up of 2,249 psig (-5,000 T-VDSS) after 447 hours. This pressure is consistent with the original OTOP pressure of 2,250 psig (-5,000 TVDSS). Additionally, an approximate six day pressure build up (PBU) test was completed in both ODST45A and ODST46 in August of 2011 yielding very similar final pressures, suggesting similar levels of depletion in this initial development area. Attachment C details the surveys and relevant data. 3.0 Results and Analysis of Production and Injection Log Surveys, Tracer Surveys, Observation Well Surveys and any Other Special Monitoring Surveillance equipment was placed in the production liner of ODST-46 to assess oil and water production conformance along the lateral via target fluid tracers which were monitored and analyzed by collecting surface fluid samples over time. Initial data indicate adequate tracer concentrations are being returned in the produced fluids. A quantitative analysis is in progress. Page 1 of 6 4.0 Review of Pool Production Allocation Factors and Issues Over the Year Production from the Oooguruk-Torok, Oooguruk-Kuparuk and Oooguruk-Nuiqsut pools is commingled at the surface into a common production line. Allocation between the pools is based on ratio of total production for a pool to the total production for the Oooguruk Unit. The pool allocation factors for 2011 are: Oooguruk-Kuparuk Pool: 50.3% Oooguruk-Torok Pool: 6.6% Oooguruk-Nuigsut Pool: 43.1% Theoretical production for individual wells for all pools is calculated on a daily basis. During 2011 wells were produced with chokes at 100% most of the time. Daily theoretical production for a well was calculated using the data from the most current well test and the amount of time a well was on production for a given day: Minutes produced 1440 Minut%day xDailyRate(BOPD)we,,,es, = TheoreticalDaily Production The daily allocation factor for the unit is calculated by dividing the actual total production for the day by the sum of the theoretical daily production for each individual well. Daily allocated production is assigned to each well by multiplying its theoretical daily production by the daily allocation factor. The average daily allocation factor for 2011 was 0.92. 5.0 Reservoir Management Summary The Alaska Oil and Gas Conservation Commission (AOGcq issued pool rules under Conservation Orders No. 645, 596 and 597 for the Oooguruk-Torok, Oooguruk-Kuparuk and Oooguruk-Nuiqsut reservoirs, respectively. Subsurface development of the Oooguruk Unit is done with dedicated development wells to the Oooguruk-Torok, Oooguruk-Nuiqsut and Oooguruk Kuparuk oil pools with no subsurface commingling. Unitized substances produced from the three oil pools are commingled on the surface. As of January 2012, there are two producing Torok wells, one of which, ODST-46 is a pre - produced injector. One additional producer, ODST-39 has been drilled and completed, and will be completed and placed on production in 2012. Injection will commence into ODST-46 after review and approval of an Area Injection Order for the OTOP Page 2 of 6 ATTACHMENT A Map of Torok Well Locations Page 3 of 6 ADL389956 ADL389955 C ADL379301 AD_389960 ADL389959 ADL389958 r r AD! 589954 AOL389953 � z AD'_S89950 ADL389WO ODST *1c ODS' 39 ADL355057 ADL350£ r C 5A s ADL389952 ADL389951 i Legend ADL355039 ADL355038 � ' Torok PA N Unit Boundary w+E F --I Lease Boundary S _ s Township Boundary Miles 0 0,5 1 2 4 Page 3 of 6 ATTACHMENT B Voidage Balance by Month of Produced Fluids and Injected Fluids 2011 Injected Fluids Year Produced Fluids Total Year Cum since Formation Import Gas, Water. Injection, Total Year Cum since MRB MRB MRB Water, Voidage, Cum, start-up, Month Oil, MRS Free Gas, MRB MRB MRB MRB MRB Cum Since Start -Up 0 0 0 0 0. 634 Jan -11 9 0 2 12 12 646 Fetr11 14 3 6 23 35 669 Mar -11 12 0 4 16 51 685 Apr -11 6 6 5 17 68 702 May -11 1B 21 6 45 113 747 Jun -11 26 46 6 78 191 825 Jul -11 22 56 5 82 273 907 Aug -11 14 35 1 50 323 957 Sep -11 18 37 4 59 382 1016 Oct -11 19 37 7 63 445 1079 Nov -11 t6 28 6 50 495 1129 Dec -11 13 23 4 40 535 1169 2011 Totals 187 291 57 535 Injected Fluids Page 4 of 6 Nat 1 njection (injection - Production) Net Year Cum since Total Year Cum since Formation Import Gas, Water. Injection, Cum, start-up, Gas, MRB MRB MRB MRB MRB MRB -16 51 -685 -17 58 0 0 0 0 0 0 0 0 0 0. 0 0 0 0 0 0 0 0 0 -50 0 0 0 0 0 u 0 0 0 0 0 0 0 0 0 0 0 0 n 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Page 4 of 6 Nat 1 njection (injection - Production) Net Year Cum since Injection, Cum, start-up, MRB MRS MRB -634 -12 -12 -646 -23 -35 -669 -16 51 -685 -17 58 -702 -45 -113 -747 -78 -191 -625 -82 -273 -907 50 -323 -957 59 -382 -1016 -63 -445 -1079 -50 -495 -1129 -40 -535 -1169 -535 ATTACHMENT C 2011 Form 10-412 Pressure Report for Torok (Revised) S -,A, -,E rjP: ALAS KA ALASKA OIL AND C.4-7- '-'j ' '7-=- RVATION COWSSON RESERVOIR PRESSURE REPORT Pioneer Nelural ReaDurras AJasM 73:1 (4 S` -eat, Sat " 0. Ail -a It RK 95507 3. UOG14-01-wMmt. Coegarup 4. :Xv % Re,.vt:t'ct! VzI 3%yicy. S wellName-snl 5 API 1umLcr '-ql I i. ADGCC 12. Zona .9J,.,_ Nuntw SDXKXKXXKKKKKK 5" poolco" utticrt 7-1 MO I *W11 I -Mill" 120 0. 1 7 cy 4944 5117 srlal Pau 131 4 -t I hereby certify that the fatagamg a true *no rorract to the best of my knowledge. t�. 7 TOO r Page 5 of 6 44M 6050001F N hf,4ryjOF 13 tl0 30006F N 6=000F k .i4",COODF k 444 ATTACE MENT D Torok Reservoir Pressure Map -- August 2011 ATTACHMENT D Tore Reserver Pressure Meds —August 2011 IIAO27i Mom Bono 4 �EPSOW$4 ftm"ra M*rc*W CAfb lossSphemid Wh"I "W, 1100 00 00W. 0A 00 OOP4 Al MMAMYN PLANT! EbNH6 Page 6 of 6