Gas Well De-Liquification Workshop Denver, Colorado February 27 - March 1, 2006 Problem Identification, Candidate Selection, & Selection of Artificial Lift Technique Rick Hornsby – Breakout Coordinator

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 2 Good surveillance & identification of problem wells What specific data do we need to look at (tubing size, casing size, liner size, flowing tubing pressure, etc.)? How do we determine a well’s critical liquid loading rate? What can we learn from evaluating historical production plots? What do the liquid (water, condensate) rates, or lack thereof, tell us?

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 3 Discussion Summary – Identification of Potential Candidates for Artificial Lift –Chemical composition, salinity of water? –Condensate or oil? –Reservoir temperature –Baseline – production when well was flowing OK. –Tubing pressure, casing pressure, tubing size. –Casing and tubing integrity. –Corrosion inhibition needed? –Fluid level. –Well’s IPR, Static BH Pressure, Flowing BH Pressure. – Well’s decline rate. – Decline rate vs. cum’l production. – Nodal analysis. – System analysis. – GLR. – Calculated gas velocity. – Presence of slugging. – Available facility. – Gathering lines, compression. – Compare actual performance vs. model of gas well performance.

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 4 Selection of those problem wells where artificial lift will result in an economical investment What can we learn from our lease operators about well performance? What operations techniques lead us to believe a well is a good artificial lift candidate (soap sticking, intermitting, stop-cocking, venting, swabbing, etc.)? What low cost actions can be taken to ‘prove up’ a good candidate (soap sticks, batch soap treatments, swabbing, flowing bottomhole pressure surveys, etc.)

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 5 Discussion Summary – Selection of Candidates for Artificial Lift –Obtain Operator’s feel on liquid cuts, or gas and liquid rates. –Obtain Operator’s feel on sensitivity to back pressure. –Understand Operator’s problems keeping wells on production – soaping, stop cocking, etc. –Hold well reviews. Talk to Operators. Supplement well file. –Provide field training of engineers. –Run integrity surveys – check for fill. –Use coiled tubing with N2 or CO2 cleanout. –Use stimulation to reduce water blocks in near-wellbore area. Do lab analysis first. –Can’t necessarily count on batch treatment to confirm or rule out suitability for cap tube. Be careful. –Can use a portable cap tube to reduce “testing” cost.

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 6 Selection of the most appropriate type of artificial lift What makes a good plunger lift candidate? What makes a good surfactant injection candidate? When is it necessary to consider more costly types of artificial lift (rod pumps, ESP’s, jet pumps, progressing cavity pumping, gas-lift, wellhead compression, etc.)? Do ongoing operating expenses matter and can the answer to this question determine the selection of the technique in the first place? How important are electronic flow measurement and automation (remote well control) to the success of the system?

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 7 Discussion Summary – Selection of Type of Artificial Lift For plungers: –ROT is 400 cf/bbl/1000 ft. –Not below 2 3/8 or 2 7/8 tubing size. –No holes in tubing, or insert profiles. –Not too high GLR. –Conventional vs. slim hole completion – communication with annulus. –Plunger depth vs. depth of perfs. –Up to 30 o from vertical, not have doglegs.

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 8 Discussion Summary – Selection of Type of Artificial Lift For surfactant: –High WCR. –Holes in tubing don’t rule it out. –Tubing ID doesn’t need to be unobstructed. –High deviation is OK. –Low Operator / Service Company crew availability.

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 9 Discussion Summary – Selection of Type of Artificial Lift For pumps: –Need to obtain very low FBHP. –Electricity or other power source at well site. –Amount of water that needs to be produced – beyond limit for plunger or chemical. –Gas interference is a problem. –Intervention costs may be high. –Safety issues with sour gas wells. –CAPEX. –Subterranean hydraulic driven rod lift a possibility. –Depth limits, deviation, dog legs, rod wear must be considered. –May choose PCP if have solids.

Feb Mar. 1, Gas Well De-Liquification Workshop Denver, Colorado 10 Discussion Summary – Selection of Type of Artificial Lift Automation: –Needed regardless of type of artificial lift. –High value of gas. –Pressure on operating staff. –Essential for focus on HSSE.