PTTC Workshop Provides Insights Into Horizontal Tech

(Tech Connections Column, January 2012, American Oil and Gas Reporter)

In December, the Tertiary Oil Recovery Project at the University of Kansas and the regional Petroleum Technology Transfer Council sponsored a two-day workshop, “Horizontal Drilling and Completion in the Mississippi Lime.” The focus was on the Mississippi Lime in Kansas, but many of the elements were broad tutorials on drilling and completions in hydraulically fractured horizontal wells.

The workshop was an early sellout and will be presented again this spring. However, each presentation can be viewed for nominal charge on TORP’s website at www.torp.ku.edu.

For those with a specific interest in the Mississippi Lime, presentations on the geology by Salvotore Mazzulo of Wichita State University, horizontal drilling operations in the Mississippian by Dean Pattison of Woolsey Operating Company, and Kansas rule changes for the Mississippian by Doug Louis of the Kansas Corporation Commission should be of interest. A panel discussion taking questions from the audience is full of specific information as well.

The four other presentations are more broadly applicable to horizontal drilling and completion operations in a variety of geologic settings.

Shari Dunn-Norman of the Missouri University of Science and Technology presented an extensive talk on horizontal completion methods, emphasizing geomechanical aspects considering the target formation, depth, reservoir thickness, porosity, permeability, stresses, and trapping mechanisms. She provided a full discussion of fracture design variables and then addressed the following questions:
  • How should the well be completed–cased or open hole?
  • Where should the well be completed?
  • How does one determine the number and length of completions for a well?
  • What fracturing fluid best fits a given scenario? What are the trade-offs?
  • What is the appropriate pumping speed based on specific variables?
Dunn-Norman also gives specific examples from the Mississippi Lime.

Jeff Chestnut, representing Packers Plus, discussed the advantages and disadvantages of open hole completions in the Mississippi Lime. Much of the talk was supported by case studies from the Mississippi Lime and Granite Wash plays, showing differences between cased and open hole multistage completions. He showed published trend data for a number of stages, and differences in production versus time and number of stages in Bakken Shale completions. Chestnut supported his points with case studies from the Montney Shale, Cleveland Sand and Granite Wash, as well as with microseismic results. Interspersed were a lot of slides showing Packers Plus’ latest open-hole completion technology, but I was impressed with the field data.

Jacob Hout, representing Pason Systems Corporation, gave a tutorial on geosteering and remote geosteering. While these services are for hire, mid- to large-size independents frequently have a geosteerer or geosteering group to assist in drilling laterals. Putting the hole not only in the right formation, but also in the designed portion of that formation, makes a big difference in production. Hout presented the various logging tools that might be chosen as the basis for geosteering, and the advantages/disadvantages of azimuthal versus omni-directional tools. Well founded organization and communication plans are critical to success in real-time steering. He included an example of how geosteering functions and discussed the challenges of geosteering.

Pat Howard, representing Baker Hughes, talked about logging applications for horizontal drilling. His presentation was a rather complete inventory of Baker Hughes’ logging and horizontal completion technology, with a significant section on casing and tubing inspection. The value is in the inclusiveness of what is available–at least from Baker Hughes–and how the services can be employed in reservoirs such as the Mississippi Lime.

On another topic altogether, the cover article in the December PTTC newsletter (available at www.pttc.org) describes a small California independent’s experience about a decade ago trying to employ a great technological solution in the face of a morass of regulatory hurdles. The technology was employing a gas turbine to burn stranded sour gas to produce electricity to cut the operator’s electric bills. The standard sour gas treatment was flaring.

This story reminds me of a request I chased about the same time for a West Texas independent who wanted to use the same concept with his marginally producing oil wells. The Texas Railroad Commission permitted the company to flare the gas, which was the standard treatment. However, if the company burned the gas and extracted useful work from it (generating electrical power in this case), it was subject to an entirely different set of regulations that required it to clean the sour gas first, then burn the clean gas in the turbine.

Of course, the cost was prohibitively higher, so the company abandoned the project. Little did I know that another independent would successfully install a turbine generator that eventually would be permitted. Its trials were far greater than I could have imagined, however. Read the newsletter article to see how common sense and regulation sometimes do not mix.