In a conventional gas well, the reservoir initially has enough energy to drive the gas to surface. As the well matures and the reservoir pressure depletes, it becomes more difficult for the gas to flow naturally. Our Upwing Subsurface Compressor Systems™ (SCS) increase gas production by decreasing bottom hole flowing pressure due to higher reservoir drawdown. This increases the production rate by up to 150%, which increases cash flow and net present value. This also improves hydrocarbon recovery significantly, extending the well life and providing a healthier balance sheet.
Advantages of the SCS for Conventional Wells
In conventional reservoirs, downhole compression increases gas production by increasing drawdown close to the perforations. Effective drawdown is accompanied by higher mass flow rate from the reservoir. Larger mass flow rates can only be achieved by downhole compression, where the gas is denser due to the downhole pressure. Furthermore, increasing suction pressure close to the perforation without the pipe friction loss associated with surface compression will result in even higher drawdown on the formation.
Another benefit of the SCS is the higher gas velocity due to suction. A small increase in pressure drop by suction will significantly change the velocity of the gas and the ability to lift liquids. At lower reservoir pressure and rates, a small diameter tubing is usually required for the efficient removal of produced liquids, however the higher friction loss associated with this tubing compromises its benefits. Upwing’s SCS produces gas at its maximum well flow potential by compressing the gas near the reservoir and without the increased frictional losses that result from the smaller tubing.
Liquid Loading/ Liquid Abatement
The SCS mitigates the issue of liquid loading in gas wells by increasing gas velocity at the compressor intake and by adding thermal energy to the streams at the compressor discharge. The improved liquid lift efficiency will increase the gas and condensate production rates on the surface. In the meantime, higher liquid sweeping also removes the liquid blockage of gas flows. The increased thermal energy of the compressed gas stream prevents water condensation and paraffin deposition, particularly in condensate rich formations. In gas wells with low reservoir pressure and without active aquifer presence, it is feasible to rely on the thermal energy from compression to deliquefy such wells.
Moreover, as the reservoir pressure is reduced as it matures, gas at lower pressures can hold significantly more water vapor. The net effect of producing wells at lower bottom hole pressures by the SCS could result in lower residual water saturation near the wellbore and eliminate any water invading and blocking the pores of the gas-producing formation rocks.
The Upwing Subsurface Compression System aids in the delivery of proven developed reserves and increases the size of undeveloped reserves by providing lower abandonment pressure that enhances hydrocarbon recovery significantly. In parametric studies conducted, the SCS increased recoverable reserves by 10 to 70%.