It’s likely many of you are following activity in Oklahoma’s Sooner Trend Anadarko Basin Canadian and Kingfisher counties (STACK) play with keen interest. Since being announced in 2013 by Newfield, the STACK delineation has expanded beyond its initial core counties and extends into neighboring Blaine county where presently ¼ of rigs in the state are now drilling.
Undoubtedly, the initial activities of leading operators in the area such as Continental, Devon, Alta Mesa, Newfield, Marathon, and Cimarex are shaping the future footprint of the STACK and setting the pace (and concentration) of future development of the liquids-rich Meramec and Woodford formations in the subsurface.
In this article, I thought it might be interesting to look at the pilot well programs holistically and from the spatial perspective using maps. Specifically, I want to depict the beginning of STACK development and maturation as it unfolds through a series of maps. My focal point for this project will be the pre-cursors to full-scale development of a play- Pilot Well Programs.
Before we get to the maps though, allow me to provide some context on pilot well programs. In a broad sense, operators will undertake pilot well programs to make determinations about their acreage, its relationship to the best part of the play, and how its value can best be maximized. Depending on its purpose, a pilot may contain a single well, or groups of wells targeting the same (or different) formations. Ultimately, an operator will use the knowledge gained through pilot programs to determine how their remaining acreage should be optimally developed. You should also know that it’s not uncommon for operators to increase their understanding of a play and obtain additional operational intelligence by participating in another operator’s pilot well(s).
So, what are the operators studying through their pilot well programs? Here’s a few examples:
- formations and associated thicknesses (rock properties, bottom-hole pressure, volumetric estimates, natural fractures networks)
- completion formulas (proppant density, treating pressures, stage spacing, cluster spacing, slick water versus gel frac)
- appropriate well spacing (density)
- communication (interference) between wells during stimulation
- lateral lengths (1-mile, 1.5-mile, 2-mile)
While conducting research for this article, I’ve found there are a few types of pilot well programs taking place in the STACK – density (horizontal spacing), stimulation (completion recipe) and risk assessment. The most common pilot type in the STACK are density pilots. Density pilots, more commonly referred to as spacing tests, implies trying to find the optimal spacing, laterally, between wellbores in the same formation. This work is ongoing and each operator has their own take on the total number of wells per section that can be economically drilled.
The image below provides a good example of density testing strategy for one of Continental’s pilot projects. Here, Continental is representing 4 wells per section, per bench or horizon. In this scenario, the object is to determine the most economic number of laterals, they can place vertically, targeting different formations, or benches within a formation without overlapping the area above and below being effectively drained. So, CLR is placing 4 laterals in the Upper Meramec and 4 laterals in the Lower Meramec. Why none in the Middle Meramec? Because the laterals above and below it will effectively drain it without drilling a well specifically targeting it.
If there weren’t already enough considerations in density testing, here’s another factor to bear in mind. Commodity pricing may also come into play here since higher prices often cause operators to accept greater amounts of well interference in order to accelerate reserves.
Perhaps the most active operator, in terms of pilot programs, has been Continental where 6 density pilot projects have been executed in the over-pressured portion of the STACK in eastern Blaine county. These projects serve to delineate the westward expansion of the play from Canadian and Kingfisher counties while paving the way for future full-scale development of Meramec and Woodford formations on their acreage. Look for Continental’s 2017 development pattern to continue shifting westward into Dewey county as they continue to find value in the over-pressured STACK area.
Source: Continental Resources February 2017 Investor Update
In the next article, we’ll dive deeper into the topic of Pilot Well Programs by looking at well production and development drilling by the leading operators. As always, you can reach me at [email protected]. I’m always here to help.
Acknowledgements: Thanks to geologist and former colleague, Lee Wescott for sharing his knowledge of the STACK and vast experience with well pilot projects. Your insights were truly invaluable. Also, I’m grateful to Organon Data for the GIS data used to create the maps for this article.
Julie Parker has a decade of experience serving the Energy industry where she became an expert in the integration and application of geospatial technologies to exploration and production projects and workflows. Ms. Parker entered the industry in 2006 when she became the first GIS Director for Chesapeake Energy, a large independent producer of natural gas headquartered in Oklahoma City, Oklahoma with operations throughout the U.S. During her tenure at Chesapeake, Ms. Parker built and lead a robust, cross-functional GIS department that gained a reputation for developing and deploying leading edge solutions for nearly all areas of the company.