Development of a Low Shear Polymer Flow Control Technology

The primary objective of the R&D project is to develop and design a low shear process, more specifically a new valve for low shear injection of polymer which reduces the mechanical degradation of the polymer and thereby reduces the loss of viscosity with 50 % compared to the state of art. As a consequence, the injected polymer solution has significantly higher viscosity than what is possible with the technology of today, and thus increase the oil recovery from a given reservoir. In a polymer injection operation, there are several critical locations were mechanical degradation can occur, were the most important locations are in the injection valve. During this project, the critcal locations have been investigated and identified, and it has been developed new technical solutions to overcome this problem. The new technical solutions has been implemented in a new Low Shear Polymer Valve Prototype, with optimized geometry which treats the polymer solution more carefully than state of the art injection valves. This reduces the amount of degradation of the solution. It has been documented in this project, through a prototype test, that the new valve can reduce mechanical degradation with more than 50 % compared to conventional chokes. In the prototype test, the prototype was tested in parallel to a standard valve. The prototype gave 10 % degradation at 40 bar, while the standard valve gave 60 % degradation at the same conditions. A reduction in mechanical degradation from 60% to 10%, can either reduce the cost of chemicals by approximately 25% or increase the oil recovery from a given reservoir with 7 - 10 percentage point.

The overall R&D challenge in this project is to develop a flow control device which can manage a high capacity polymer flow, typically 20-150 m3/h at 40-50 bar, without seriously degrading the polymer. At these operating conditions, the state of the art chokes and control valves cause 50-70% mechanical degradation of the polymer. The scientific objective is 10% degradation, or lower. This shall include to define, rank and close all technology gaps relevant for a scaled-up, field realistic prototype installation of the new Low Shear Polymer Flow Control technology in a qualified test laboratory facility. (Statoil's new polymer test rig in Porsgrunn). We shall optimize the functionality, size and performance of the Low Shear Polymer Flow Control device and demonstrate the benefits in terms of reduced consumption of polymer and increased oil recovery. This shall further include development of equations and algorithms for sizing of hardware, and prediction of performance of different qualities of polymers in terms of reduced mechanical degradation and EOR. The project approach will be a combination of laboratory research methodology (model and full scale), theoretical (mathematics) work, empirical modelling and simulations (predictions based on experimental results). It is important to perform laboratory testing to obtain data to develop trends, empirical models and calculation tools for prediction of the polymer degradation as a function of the spiral channel geometry and size of the discs. We aim to optimize the geometry and size of the planned innovation. Reducing the degradation of polymers will lead to reduced amount of polymer injected for flooding operations, which will represent a huge cost saving for the oil companies. Simulations show that a reduction of the mechanical degradation of polymer solution caused by chokes down to 10% or lower, might increase the oil recovery with more than 10% compared to the state of the art technology.