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Artificial Lift Techbook 2019

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HartEnergy.com | April 2019 | 53 ARTIFICIAL LIFT: CASE STUDIES set, potential clients can be better reassured that the deployment of multiple couplings in this fashion will result in performance improvements unachievable with a more conventional approach. Analyzing Solution 2 In addition to all the benefits afforded by Solution 1 (wear reduction, mitigation of holes in tubing, etc.), Solution 2 offers more than 100 ToughMet couplings in a large section of the rod string to reduce sliding friction on the rod string and load- ing. When these large numbers of couplings are deployed, the operator starts to observe positive changes in their wells. Solution 2 trials: performance analysis. Twenty-two full strings and five large partials were being monitored across 14 major operators in the Permian, Bakken and West Coast. Materion collaborated with the oper- ators to analyze various metrics on these wells. The ToughMet couplings were observed and monitored to assess how they affected the performance of the wells. Observations. A number of the wells were pulled out of the data set due to the concern that special causes such as nearby fracking, for example, may distort fluid production data. Data from 16 of the wells that were considered to be reliable data sources by the production engineers was retrieved. It was observed that overall system friction was reduced, resulting in a range of benefits in production performance (Figures 1 and 2). The effects that the couplings demonstrated in the wellbore include an improvement in sucker rod string movement, decrease in mechanical loads on the polished rod and gear box, better pump fillage, increased overall system efficiency and increased fluid production. About 73% of the wells in the sample set have seen improved oil production with the average change of at least 12.6% increase in oil production. Of those tested, 78% have shown system efficiency increases and 86% of the wells demonstrated downhole stroke increase. The most notable result observed was in load reductions; 94% of wells experienced reduced gearbox loading with an average reduction of 12.5%. Regarding changes to load on the polished rod, 91% of wells experienced a smaller range between peak and min- imum load with an average reduction of 12.1%. By shortening the load range (or alternating stress) in these instances, fatigue is reduced. Statistical significance. In almost every case, the before-and-after data pairs followed a normal dis- tribution. Paired sample t-test analyses confirmed statistically different results for all of the important measured performance parameters following the installation of a full, or nearly full, string of Tough- Met couplings. The statistical analysis provides the operator with confidence about the likelihood of realizing benefits and the degree thereof. Conclusion The Solution 2 trials have proved to deliver friction reductions down to one-third of what the system was losing in the way of lifting power due to frictional losses. The stroke length of the piston inside the pump has significantly increased, the overall system efficiency, which is an overall measure of the hydrau- lic work that is done by the system relative to the amount of energy input, has significantly increased and there have been increases in production, in some cases to up to 30%. In addition, the mechanical loads on the surface equipment—the gearbox, the polish rod, etc.—have been brought down substantially. The results reported to date continue to be com- pelling; Solution 2 enhances both the runlife and the performance of rod-pumped wells. n Component % of Wells Improved Did Not Improve Oil Production 73% 27% System Efficiency 78% 22% Downhole Stroke 86% 14% Pump Fillage 73% 27% PPRL 91% 9% Load Range- Pol Rod 91% 9% Gearbox Loading 94% 6% Fluid Level AP 83% 17% Component Average Change Oil Production 12.6% Ç System Efficiency 20.6% Ç Downhole Stroke 16.0% Ç Pump Fillage 6.4% Ç PPRL -13.1% Ç Load Range- Pol Rod -12.1% Ç Gearbox Loading -12.5% Ç Fluid Level AP -23.8% Ç Figure 1. This chart depicts the Solution 2 trial results to date for average changes in efficiencies for the different measured components. (Source: Materion Corp.) Figure 2. This chart depicts Solution 2 trial results to date by measured improvement percentage for the different measured components. (Source: Materion Corp.)

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