Volume 11, No. 4th Quarter 2005

 

 Petroleum Technology Transfer Council   

        WWW.PTTC.ORG

Crossing New
Frontiers for PTTC

Historically, workshops held deep in the rural basins have been a tried and proven way to exchange technical information. In its last fiscal year, PTTC drew 8,900 attendees to the more than 150 activities it held or co-sponsored with complementary organizations. With advancing technological breakthroughs for distance learning programs, PTTC is looking at capturing these lessons and discussions for the benefit of those unable to travel to other parts of the country by presenting these online. PTTC has been posting presentations online for some time, which is drawing many people. For instance, in one of 10 regions during October this year, 10 workshop presentations were downloaded over 9,000 times—this equaled the total FY05 attendance for all PTTC-supported events.

Crossing a frontier to a new level of effectiveness, PTTC is developing modules on selected hot topics. Its first effort will be a module on "Hydraulic Fracturing," with a focus on tight gas. Several world-class speakers have already agreed to share their insights and experience for the benefit of others. Case studies will be shared to illustrate concepts. With a Houston location and effective promotion, high attendance is anticipated. We're leveraging this expertise by videotaping presentations and Q&A sessions to deliver them online so you can learn on your schedule.

cont. on page 2

In This Issue

Environmental Corner ................ 3
Tech Transfer Track ................... 4-6
State-of-the-Art Summary .......... 7-9
DOE Digest ................................ 10
Industry View ............................. 11
PTTC Tech Info ........................ 13
Upcoming PTTC Events ............ 15

PTTC is a national not-for-profit information network formed in 1994 by oil and natural gas producers. Programs are funded by matching funds from the US Department of Energy (DOE) with funds from State Governments, Universities, State Geological Surveys and Industry. This program would not be possible without contributions from the DOE Office of Fossil Energy through the National Energy Technology Laboratory (NETL).

Increasing Oil Recovery Factor

Current recovery factor in mature domestic oil reservoirs varies considerably depending on geographic region and reservoir specifics—it might be 30% average recovery in California and half that in many Midcontinent reservoirs. In both cases though, there is the potential to significantly increase the recovery factor being experienced. Two recent PTTC workshops, in Kansas and California, focused on doing just that. Addressing typical local operators in southeast Kansas, PTTC staff focused on the basics of identifying damage, quantifying additional potential, and practical approaches a smaller operator could implement.

Redeveloping State Lease PRC 186, Belmont Field
(click map to see larger jpeg)

California's reservoirs and the increased technical capability of companies operating them allows more complex approaches. PTTC's West Coast Director Iraj Ershaghi noted two basic approaches to increasing recovery—well work (workovers/redrills) and reservoir characterization that leads to additional development.

In the well work arena, factors are excessive water production, formation damage and emulsion blocking. Several regional projects have addressed controlling water production. With formation damage it is critical to really study the damage (and the solution). Proving the point on additional reservoir characterization, Ershaghi cited Tidelands' Wilmington field experience and the Venoco South Ellwood projects. There, detailed 3-D reservoir characterization and visualization identified undrained compartments that new wells are profitably draining. When taking a serious relook at a reservoir, there are insights to be gained from reservoir analog studies such as those C&C Reservoirs (www.ccreservoirs.com) has performed. Discussing their findings, C&C noted that fluid type (gas, conventional oil, or heavy oil), permeability and drive mechanism are primary factors affecting recovery.

Underbalanced drilling (UBD), often in conjunction with horizontals, is another important tool. Blade Energy Partners drove home the point that UBD means "always maintaining underbalance." Damage from overbalanced drilling is particularly problematic in horizontals. UBD may cost the same or a little more, but there are real advantages from a cost avoidance (lost circulation, rate of penetration) and recovery standpoint. With UBD it's not just higher initial production—long-term production trends indicate there is usually a true increase in estimated ultimate recovery.

Additional recovery need not be exotic. The LATA Group's nitrate-based biocompetitive exclusion process (www.latagroup.com) addresses a common operational problem, reservoir souring. Beyond this, when applied downhole, there can be a beneficial enhanced oil recovery effect from microbial byproducts. Through videotape, Mike Dennis, LATA Group's president, shared several California- and other U.S.-based case studies. Tex Boratko with Schlumberger described two of their tools that help get valuable behind pipe information: (1) the Cased Hole Formation Resistivity tool enables through pipe resistivity measurements and (2) the Cased Hole Dynamics Tester drills small holes through pipe into the reservoir, retrieves fluid samples, then mechanically plugs the holes. Fluid and pressure data are invaluable for evaluating recompletions or redrills.

Technology alone is not the complete answer. The West Coast Region's 2005 Tech Transfer Award went to Oxy and the State Lands Commission. Oxy applied high angle, extended-reach drilling to redevelop a previously abandoned (1990s) state lease in the Belmont Field. Drilling from existing Oxy facilities in Long Beach's Chaffee Island, there was minimum environmental impact. Production rates from initial wells have been quite attractive and more are planned. The State Lands Commission demonstrated permitting flexibility that allowed this redevelopment to occur.