Outline Intro What is GARP®? What problem does it solve? Why is this a problem? Why choose rod pump and gas lift? How does it work? Results to date Pros / Cons Help from Industry
What is GARP® ? Gas Assisted Rod Pump Combination of two of the oil industry’s most reliable, understood, and popular forms of artificial lift (Rod Pumps and Gas Lift)
What problem does it solve ? Reduces back pressure over conventional forms of lift currently placed above deviated sections in horizontal wells and in vertical wells that are too deep to pump or have extended perforated intervals. This practice leads to production rate reduction, pre- mature abandonment, and a loss of reserves and leases
Why do operators do this? Operators are hesitant to place lift equipment in deviated sections and into perforated intervals due to inefficiencies and high operating costs associated with gas interference, solids issues, and wear and tear on tubulars
Why choose rod pump and gas lift? Rod pump -Well known/understood -Readily available parts -Workovers can be less expensive than other forms of lift -Lowers reservoir pressure better than other forms of lift Gas Lift -Well known/understood. Low maintenance costs (downhole) -Not affected by deviated section, solids, or gas locking -For short lift distances, provides a very efficient form of lift without exerting high back pressure on the reservoir -More effective in lifting deep reservoirs than other methods
GARP® First Generation Design Designed for 7” csg or larger Applicable to mainly older horizontal wells Dual wellhead w/ two adjacent tubing strings one for gas injection and one for the rod pump Requires a small two stage compressor Gas lift raises liquids a short distance from the deviated section to above the pump. Gas breaks out and rises to the surface, liquids fall and are trapped by a packer. Once they rise above the pump, they enter the pump chamber and are transported to the surface.
GARP® Slim Hole Design Second Generation designed for wells with 4-1/2” casing or larger Applicable to nearly all vertical wells and modern horizontal wells Utilizes concentric tubing arrangement with a single wellhead Works with same principals as the larger bore design
When should GARP® be installed? GARP is most effective when other forms of artificial lift become inefficient or stop working due to liquid loading below the artificial lift equipment
GARP in the life of a well Flowing Artificial Lift -High Volume- Gas lift/ESP/Jet/PCP -Med- Low Volume – Rod Pump / Plunger/ Stop Cock/ Soap GARP® - not tested yet for rate acceleration in non-marginal wells Abandonment
Results to Date Has only been installed on company owned marginal wells Morgan Kovar #1 – Austin Chalk Horizontal well in Fayette County, Texas Selected Lands #2 – Georgetown/Buda Horizontal well in Grimes County, Texas Philips #1 – Austin Chalk Horizontal well in Grimes County, Texas Currently installing GARP® on a 10 well horizontal pilot program with an operator in the Giddings Field
Advantages of GARP® Economically recovers reserves currently being left behind Significantly extends the life of leases A very efficient gas separation design allows rod pumps to be used in gassy wells The injection string in both designs can be utilized for a much more efficient placement of chemicals (corrosion, scale, salt) Combines two of the most well established forms of artificial lift capitalizing on specific strengths and minimizing weaknesses In the Slim hole version, a standing valve prevents load water from chemical/paraffin treatments from over-whelming low pressured reservoirs. This same design also allows the pump to be flushed using load water from casing injection to free stuck pumps.
Disadvantages of GARP® Does not overcome inherent limitations of rod pumps, i.e. solids production, wear and tear on moving parts, paraffin, etc. More costly to install than rod pumps alone since another tubing string is needed; however, most of these costs are tangible. Typical costs are ~ $100-$125K (not incl pumping unit, rods, pump) A pressured gas source is necessary. A small compressor can be built for ~$35,000 or it can be rented for ~$1700/mo.
Help from Industry Need opportunities to expand the technology Wells outside of the Giddings Austin Chalk Area Vertical oil or gas wells with extended perforated intervals Vertical oil/gas wells too deep to rod pump Rate acceleration test in non-marginal wells Willing to do pilot programs for no fee