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Problem Identification, Candidate Selection, & Selection of Artificial Lift Technique. Rick Hornsby – Breakout Coordinator. 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.)?
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Problem Identification, Candidate Selection, & Selection of Artificial Lift Technique Rick Hornsby – Breakout Coordinator
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? 2006 Gas Well De-Liquification Workshop Denver, Colorado
Discussion Summary – Identification of Potential Candidates for Artificial Lift • 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. • 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. 2006 Gas Well De-Liquification Workshop Denver, Colorado
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.) 2006 Gas Well De-Liquification Workshop Denver, Colorado
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. 2006 Gas Well De-Liquification Workshop Denver, Colorado
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? 2006 Gas Well De-Liquification Workshop Denver, Colorado
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 30o from vertical, not have doglegs. 2006 Gas Well De-Liquification Workshop Denver, Colorado
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. 2006 Gas Well De-Liquification Workshop Denver, Colorado
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. 2006 Gas Well De-Liquification Workshop Denver, Colorado
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. 2006 Gas Well De-Liquification Workshop Denver, Colorado