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Home My WebLink About2009 Pretty CreekChevron Paul Winslow Chevron North America Petroleum Engineer Advisor Exploration and Production MidContinent/Alaska SBU erpoint Dr., Ste 100 Anchorage, AK 99503 Tel 263-7629 Email pwinslow@chevron.com February 22, 2010 RECEIVED Mr. Dan Seamount, Chairman FEB 2 3 2010 Alaska Oil and Gas Conservation Commission 333 W. 7th Avenue, Suite 100k80N8G�IC011�.001ri11lli0n Anchorage, AK 99501 AfIL110f1W Re: 2009 Annual Performance Report: Material Balance Calculations of Production and Injection Volumes Pretty Creek Gas Storage Facility Pretty Creek Unit #4 Dear Commissioner Seamount: Attached for your review is the 2009 "Annual Performance Report" for the Pretty Creek Gas Storage Facility - Pretty Creek Unit #4 (PCU#4), as required by AOGCC Storage Injection Order No. 4 (SIO#4). This report contains material balance calculations of production and injection volumes from the inception of primary production, through 2009 gas storage operations. Attachment #1 is a table of monthly gas production and injection volumes for the PCU#4 well through February 21, 2010. The table includes all production and injection volumes beginning with the commencement of primary production in December 2001. Note that from December 2001 through April 2004, primary production was from both the 51-5 and from the 45-0 reservoirs. It is estimated that 1.286 Bcf of gas was produced from the 45-0 sand. On May 1, 2004, the 45-0 sand was isolated and the remaining primary production, as well as all gas storage operations (beginning in Nov. 2005), was from the 51-5 sand. Gas injection was initiated into the 51-5 sand in PCU#4 on November 15, 2005 and by July 1, 2007 the reservoir was within approximately 0.14 Bcf of being full. From October 2007 through July 2009, the 51-5 gas storage reservoir was cycled twice. Approximately 246 MMcf of gas was produced during the 2007/2008 winter, 366 MMcf injected in the summer of 2008, 585 MMcf produced during the 2008/2009 winter, and finally 612 MMcf of gas injected back into the storage reservoir during the summer of 2009. The 2009 summer injection filled the 51-5 reservoir to approximately 6 MMcf above its original gas in place. Due to the mild temperatures realized this winter, gas from the 51-5 storage reservoir has not been produced and the reservoir is currently still full. PCU #4 has been shut-in since July 31, 2009 and currently has a SITP of 1,478 psig. This equates to a shut-in BHP of 1,624 psia. Note that the original 51-5 reservoir pressure was estimated to be 1,659 psia. Attachment #2 is a table of calculated reservoir pressures over the life of the storage operation, with the associated cumulative gas voidage (production - injection) at the time of the pressure estimates. These pressures (divided by their respective Z -factors) are plotted versus net cumulative gas withdrawn on a standard P/Z plot (Attachment #3). MidContinent/Alaska SBU/Chevron North America Exploration and Production www.chevron.com Pretty Creek Gas Storage Facility 2009 Annual Performance Report Page 2 Viewing the P/Z plot (Attachment 3), the 2009 injection cycle data followed in line with the previously established injection and production cycles measured in 2007 and 2008. This is a good indication that storage operations within the 51-5 reservoir have been contained. Also the fact that the current reservoir pressure is very close (35 psi) to the estimated original reservoir pressure, shows very good gas containment. If you have any questions regarding this annual performance report, please contact Paul Winslow at your earliest convenience. Sincerely, Paul M. Winslow Petroleum Engineer Advisor Cc: Dave Whitacre Attachments Union Oil Company of California / A Chevron Company http://www.chevron.com ATTACHMENT #1 PCU #4 PRODUCTION AND INJECTION VOLUMES Primary Production from both 51-5 and 45-0 Sands - Cumulative gas produced from the 45-0 Sand = -1,286 MMcf Gas Storage (since Nov. 2005) only in 51-5 Sand Month Monthly Gas Prod MCF Monthly Gas Inj MCF Cum Gas Withdrawn MCF Month Monthly Gas Prod MCF Monthly Gas Inj MCF Cum Gas Withdrawn MCF December -01 80,465 - 80,465 January -02 195,929 - 276,394 January -06 - 2,719,005 February -02 196,257 - 472,651 February -06 - - 2,719,005 March -02 220,869 - 693,520 March -06 - 104,423 2,614,582 April -02 165,533 - 859,053 April -06 - 163,320 2,451,262 May -02 26,375 - 885,428 May -06 - 3,281 2,447,981 June -02 31,104 - 916,532 June -06 255 - 2,448,236 July -02 10,746 - 927,278 July -06 263 2,448,499 August -02 - - 927,278 August -06 263 - 2,448,762 September -02 33,163 - 960,441 September -06 878 169,962 2,279,678 October -02 183,163 - 1,143,604 October -06 - 140,560 2,139,118 November -02 157,256 - 1,300,860 November -06 2,983 96,880 2,045,221 December -02 138,233 - 1,439,093 December -06 - 120,096 1,925,125 January -03 117,103 - 1,556,196 January -07 49,440 85,109 1,889,456 February -03 85,932 - 1,642,128 February -07 3,706 85,162 1,808,000 March -03 79,775 - 1,721,903 March -07 58,089 74,450 1,791,639 April -03 17,030 - 1,738,933 April -07 - 184,212 1,607,427 May -03 196 - 1,739,129 May -07 - 116,641 1,490,786 June -03 - - 1,739,129 June -07 - 64,573 1,426,213 July -03 25,313 - 1,764,442 July -07 - - 1,426,213 August -03 20,306 - 1,784,748 August -07 - - 1,426,213 September -03 16,087 - 1,800,835 September -07 - - 1,426,213 October -03 9,758 - 1,810,593 October -07 339 - 1,426,552 November -03 3,544 - 1,814,137 November -07 94 - 1,426,646 December -03 52,856 - 1,866,993 December -07 37,071 - 1,463,717 January -04 57,353 - 1,924,346 January -08 99,982 - 1,563,699 February -04 55,318 - 1,979,664 February -08 107,659 - 1,671,358 March -04 45,931 - 2,025,595 March -08 634 - 1,671,992 April -04 - - 2,025,595 April -08 283 - 1,672,275 May -04 56,583 - 2,082,178 May -08 - 128,809 1,543,466 June -04 70,263 - 2,152,441 June -08 114,230 1,429,236 July -04 21,267 - 2,173,708 July -08 - 105,813 1,323,423 August -04 74,030 - 2,247,738 August -08 290 1,636 1,322,077 September -04 41,208 - 2,288,946 September -08 9,220 15,228 1,316,069 October -04 83,626 - 2,372,572 October -08 122 - 1,316,191 November -04 80,884 - 2,453,456 November -08 73,656 - 1,389,847 December -04 71,571 - 2,525,027 December -08 201,815 - 1,591,662 - January -05 62,310 - 2,587,337 January -09 215,323 - 1,806,985 February -05 54,328 - 2,641,665 February -09 84,921 - 1,891,906 March -05 55,460 - 2,697,125 March -09 - - 1,891,906 April -05 57,247 - 2,754,372 April -09 66 - 1,891,972 May -05 53,045 - 2,807,417 May -09 37 194,423 1,697,586 June -05 40,800 - 2,848,217 June -09 - 206,712 1,490,874 July -05 40,964 - 2,889,181 July -09 - 211,061 1,279,813 August -05 37,981 - 2,927,162 August -09 - - 1,279,813 September -05 8,872 - 2,936,034 September -09 - - 1,279,813 October -05 - - 2,936,034 October -09 - - 1,279,813 November -05 - 59,329 2,876,705 November -09 - - 1,279,813 December -0511 157,700 2,719,005 1 December -09 390 - 1,280,203 ATTACHMENT #1 PCU #4 PRODUCTION AND INJECTION VOLUMES Primary Production from both 51-5 and 45-0 Sands - Cumulative gas produced from the 45-0 Sand = —1,286 MMcf Gas Storage (since Nov. 2005) only in 51-5 Sand Month Monthly Gas Prod MCF Monthly Gas Inj MCF Cum Gas Withdrawn MCF Month Monthly Gas Prod MCF Monthly Gas Inj MCF Cum Gas Withdrawn MCF January -10 250 1,280,453 February -10 - - 1,280,453 March -10 1,280,453 April -10 1,280,453 May -10 1,280,453 June -10 1,280,453 July -10 1,280,453 August -10 1,280,453 September -10 1,280,453 October -10 1,280,453 November -10 1,280,453 December -10 1,280,453 C m E E O U m (A a 0 O Z m N w N F - w m m E m N F ov E - _ m w ate+ O 15 = E CL .n 0 � = m UU C E _ = t @ ++ .a in a. o L CL N a c 0 o Z W 3 w N Q rE m H d Z Q m C, � .a > N a = ( N O E a� V r mmn. a =moo (� N N a0 F- 0 O Z m N w N F - 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