Experience of a long stroke deep well pumping unit operation for hard to recover oil reserves production

A number of factors adversely aff the operation of the commercially available oil well pumping units, especially in wells with high viscosity production, which requires development of a high performance installation, in particular for such oil wells. The adverse eff of a part of these factors decreases with the increasing stroke length of the plunger. The stroke length of the previously designed installations ranges from one to hundreds of meters. Based on the conducted experiments, the optimal acceptable stroke length has been determined for the developed Long Stroke Deep Well Pumping Unit DGNU-2-2.5. where the traction element for the string of rods is a round-link chain, which is attached to a chainwheel performing bidirectional rotation. The designed equipment provides the following: smooth adjustment of the length and speed of the plunger's up and down movement in accordance with production capabilities of the well, remote monitoring, saving and changing of parameters, protection against exceeding the set parameters, etc. DGNU-2-2.5 unit is certifi its commercial manufacturing has been launched, and it has been implemented on 35 wells in various oilfi ds so far.
Materials and methods
Industrial experiments and testing of a long-stroke deep-pumping unit.
Results
For the period from 2010 to 2018, the DGNU units were introduced on 35 wells of the producing companies of Sheshmaoil Management Company LLC: • on 23 oil wells in JSC Sheshmaoil; • on 7 oil wells in JSC Ideloil; • on 5 oil wells in JSC Geologiya. 4 wells have been demothballed. On some wells, the fl fl w rate increased almost 2-fold after the introduction of DGNU-2-2.5. For example, it increased from 0.6 t/day to 1.1 t/day on the well No.412 at 3% and 0.7% watercut, respectively, and with the oil viscosity 87 cSt; from 2.8 t/day to 4.4 t/day on well No.3750 at 5% and 4% watercut, respectively, and with the oil viscosity 137 cSt. Following the introduction of DGNU-2-2.5, the pump delivery rate has increased, for example, from 0.34 to 0.95 on the well No.412, and from 0.57 to 0.86 on the well No.3750. Energy savings in operation of DGNU-2-2.5 were up to 70% on some wells compared with pumpjack. A certain experience has been accumulated in working with such an installation, its maintenance and repair.
Conclusions
1. The designed DGNU-2-2.5 Long Stroke Deep Well Pumping Unit provides an eff e recovery of the oil well products, in complicated conditions as well. 2. The DGNU-2-2.5 unit has successfully passed fi d and acceptance tests, its batch production was launched.