The production of the shale oil well at start up can produce high fluid rates with a high energy causing it flow naturally. After this stage, a high rate artificial lift systems such as ESP or Gas lift is required. But because of the rapid depletion of the stimulated zone during the first year (between 60 – 80% in Eagle Ford), the most flexible form of artificial lift available is used, the beam pumping.
Because the pump depth could reach between 4000 up to 12000 ft., the beam pumping system is limited in flow rate. A big surface pumping unit and high strength rod are necessary. Other complex challenges to overcome are the combination of crooked or highly deviated well bore, high GOR, propant or sand flow back and the presence of H2S. Small tubing completions in shale wells, with 2 3/8” tubing installations, pushes the system to provide high fluid velocity with effective solids transportation in low rates and more inexpensive equipment but with sucker rod diameter restriction to 7/8” slimhole couplings.
Optimizing artficial lift equipment selection , sizing and design with ensure longevity of the equipment and continued production. A premiun sucker rod connection has a design that allows the use of 7/8" and 3/4" strings tapers with KD material to work in corrosive environments with regular size pumping units and lighter strings with guide when neccessary in wells where 1" and high stregth rods should be the conventional alternative.
This paper explains the experiences of more the 70 strings installed and the benefits achieved for a major operator working in the Eagle Ford formation.