Operators in the Barnett Shale play and elsewhere have long used measurement while drilling (MWD) and logging while drilling (LWD) to gather the gamma ray and other attributes to "geo-steer" the well trajectory to the desired zone. Recently, geo-steering has been taken a step further to detect faults and other vertical discontinuities, avoid certain problem zones, and to help design the frac—in other words, "geo-navigating." Well control and surface seismic do not provide the information needed for the optimal trajectory in this complex formation. In particular, water-bearing faults and other vertical discontinuities, such as the boundary of a collapsed-breccia zone or the edges of a homogenous reef, can now be detected and avoided. The underlying Ellenberger Group, which is also frequently water bearing, can be identified and avoided. Geo-navigating enables the driller to get to the target with the least expense and fewest problems and facilitates the planning and design of the fracture stimulation of the horizontal well to maximize hydrocarbon production, while avoiding water.

Excerpted from "Barnett Shale Operators Extend Geo-Steering to 'Geo-navigation'," World Oil, August, 2006. p. 91. Available online at www.worldoil.com/
Magazine/MAGAZINE
_DETAIL.asp?ART_ID=2967
&MONTH_YEAR=Aug-2006.

determine the proper number of frac stages, the coverage effectiveness of those stages, the ideal spacing between adjacent laterals, the height coverage and an indication of early productivity using proprietary correlations of mapped volume to Barnett production." Operators are using this technology increasingly to optimize production and to avoid water zones and faults, maximizing contact with the natural fractures throughout the lateral.

Merrick Systems has developed and bench tested RFID tags designed to withstand the high pressures and temperatures of deep drilling. These relatively inexpensive tags can be installed into drill pipe, collars, or any other downhole equipment. They transfer data via a low-level radio signal to nearby reading components. The information they provide to the operator documents the what, where, when and how each downhole component was manufactured, reducing operational risk while maximizing the life of the components. The tags have been bench tested to 20,000 psi and 272 °F. Higher temperature bench testing and field testing will be ongoing.

Advances in technology—measurement, control, and communications—have not only made production automation affordable, it is essentially a necessity to extend production, reduce costs and improve bottom lines. Even small operators are discovering the payout for automation is measured in weeks or months, and the benefits in years. These benefits include:

• Increased production through lift optimization and minimized down time

• Reduced operating cost—labor, maintenance

• Improved safety and environmental protection

• Improved staff utilization

• Improved business and regulatory reporting through improved data gathering

Studies have shown production increases on the order of 5–20 percent and cost reductions on the order of 10–35% are achievable. The obvious savings is in labor, the elimination of the need to visit each location daily and take measurements or respond to problems. In addition, a production automation system can provide remote control, highlight problems, often before they happen, and assist in the solution to any problems it detects. Compared with the early systems, the upfront costs are low, the operating costs are low, and the potential to improve business is high.

Generally speaking, there is no one-size-fits-all system. Based on the individual needs and type of well and type of lift, the systems can be customized to maximize the results. One specialized application where it has shown to be effective is in the monitoring of remote locations. Not only are there significant labor savings in receiving data and controlling wells at a central location, but also when a problem occurs, the person dispatched to solve the problem arrives equipped to take the appropriate action. Another example of a specialized smart system is Kerr-McGee's utilization of smart, wireless, multi-well, plunger controllers in the Wattenberg field of Colorado, with the capability of controlling and allocating natural gas and oil volumes while providing real-time well tests. The controller adjusts the plungers in response to line pressure and coordinates the on and off time to share one separator with a number of wells, one at a time. And finally, a unique system of controls has been installed at a steam flood pilot in the Powder River Basin. This system monitors and controls the steam generator, injection wells and producing wells from a central location to optimize production and update a 3-D reservoir model.