What's new in production

	Vol. 224 No. 3
ROBERT E. SNYDER, EXECUTIVE ENGINEERING EDITOR

 N₂ injection pilot. Talisman Energy Inc. has commenced a nitrogen injection pilot project at its Turner Valley oil field in Alberta, Canada. This EOR project is the first of its kind in Canada. A three-year evaluation period is planned to demonstrate that N₂ can be injected into mature oil fields to increase recovery of oil and natural gas liquids. A successful pilot would be expanded and lead to full-scale development. 

 The company’s President/CEO Dr. Jim Buckee, says, “By applying new technology to the project, we expect to revitalize this historic Canadian field. The field contained an estimated one billion barrels of OOIP, of which only 15% has been recovered. An incremental 3 – 10% from the nitrogen flood has the potential to increase oil recovery by 30 – 100 MMbbl and extend remaining field life beyond 20 years.”

 Talisman has an average working interest of 60% in the four oil units that comprise the pool. Investment for the pilot in 2002 will be $8.5 million in Turner Valley Unit No. 4. Oil production began in Turner Valley 65 years ago and the field has been under waterflood for 40 years. Talisman’s project design uses a membrane technology to extract N₂ from air, which may offer a cost-effective alternative to the cryogenic technology used elsewhere. Capital cost efficiencies may be achieved through use of suspended wellbores as injectors and integration of N₂ facilities with existing equipment. 

 Downhole acid generation. A novel system that uses enzymes to boost production of oil/gas wells, while offering greater protection to rig workers and the environment, has been developed by a UK company. In the new technique, a patented fluid called Arcasolve uses specific acid precursors and enzyme (protein) catalysts to produce acid, typically acetic, in the wellbore or adjacent rock formation once the fluid has been pumped downhole. The in-situ acid generation offers advantages in a number of acidizing applications, especially for cleaning up water- or oil-based drilling mud cake damage. 

 Successful results from a pilot project on an offshore well in Africa were reported in a recent SPE conference. This data demonstrated that applying the method to stimulate petroleum production from wells could make millions of dollars over a well’s life. The fluid was developed by Cleansorb, a company based on the Surrey Research Park at Guildford, Southern England. There, biotechnologists Ian McKay and Ralph Harris spent seven years and a lot of money perfecting Arcasolve.

 The method has been granted millennium product status by the UK Design Council, in recognition of its potential to change oil industry working practices. Now, the technology is to be marketed worldwide by Halliburton Energy Services. With up to 50,000 wells being drilled each year, Cleansorb believes its potential market is worth at least a billion pounds annually. For the last 100 years or so, clean-ups have involved pumping large quantities of hydrochloric acid into wells, a task fraught with potential safety and environmental problems. This approach is also less effective on modern horizontal wells introduced to exploit narrower oil/gas strata, where the quick acting HCl tends to react at the point where it is introduced; and achieving uniform acidizing across the whole, long horizontal wellbore is not easy. 

 Arcasolve in-situ acidizing solves several key problems inherent in conventional treating, and has additional operational advantages. Because it is noncorrosive and nonreactive when placed in the well, this ensures an even distribution of the fluid across long horizontal or directional producing sections with minimal leak-off during pumping. Once it has been introduced into the wellbore or formation, acid is produced in-situ during shut-in. Independent lab testing has demonstrated its effectiveness for removing drilling mud damage with typical, regained permeabilities up to 97%. In tests on carbonate cores, not only was damage removed, but permeability increases of up to about 700% were attained. The pH created by the fluid is also optimal for polymer-breaking enzyme activity. 

 The company is also developing other enzyme-based processes. It recently concluded a project to investigate their use in a process to tackle scale buildup. Work is continuing on this process in collaboration with a major oilfield chemical supplier. 

 Deepwater US Gulf 2002 projects. The US Minerals Management Service (MMS) says there were 12 discoveries in the deepwater US Gulf of Mexico last year, and that 14 deepwater projects began oil and gas production, tying a record set in 2001. “Calendar year 2002 was a year of significant deepwater activity in the Gulf despite the general downturn in drilling,” said MMS’ GOM Regional Director Chris C. Oynes. “Twelve new deepwater discoveries were made and three of these were in 8,000 ft or greater water depths.”

 MMS said that the 14 new producing fields increase the Gulf’s total to 65. Deepwater development projects continue at a fast pace and the 14 new projects include 11 that were subsea production systems tied back to another project. This raises the total number of subsea projects to 41 out of the 65 total deepwater projects. Three of the new deepwater starts utilized a spar as a production system. MMS expects a significant rise in the number of deepwater projects that will start production in 2003, perhaps as many as 19. 

 In a related project, MMS has approved use of the world’s first cell spar in a deepwater oil and gas project. The approval came as part of a Conceptual Deepwater Operations Plan (DWOP) review of Kerr-McGee’s Red Hawk project, to be located in 5,300-ft water. Kerr-McGee operates Red Hawk with 50% interest, Ocean Energy holds the remaining 50%. 

 Red Hawk is located on Garden Banks Block 877 and will be developed using this new technology – the world’s first cell spar and the second permanent use of synthetic moorings in the US Gulf. This innovative spar, which is the third generation of spar technologies, reduces the reserve threshold needed for an economical development in deep waters. Kerr-McGee has selected Technip Offshore, Inc. to construct the cell spar for the development.