Dalia/Camelia Polymer Injection in Deep Offshore Field Angola Learnings and In Situ Polymer Sampling Results

Abstract

The Polymer Injection Project on Dalia field, one of the main fields of Block 17 in deep offshore Angola, is a world first for both surface and subsurface aspects. Thorough geosciences and architecture integrated studies led to decide to phase the project, with a polymer injectivity test on one single well, followed by a continuous injection of polymer on one of the four subsea lines delivering water to the field. The single well injectivity test on DAL-710 was completed first quarter of 2009, just two years after first oil. Very successful results led to launch a polymer injection pilot on the full injection line of the Camelia reservoir. The main objectives of the single line Camelia pilot were to confirm long term operability and injectivity of polymer in the specific conditions of this deep-offshore development, and measure the in situ viscosity (sampler well) of the injected polymer solution away from the injector, as key inputs to the evaluation of an extended project. From February 2010 to August 2012, a 900 ppm polymer solution was injected through the three wells of the line. In summer 2012, a sampler well was drilled 80 m far from one of the injector, located behind the polymer front thanks to 4D seismic monitoring. MDT and bottom hole samples were done and analyzed. The paper describes the main results of the pilot phase on injectivity, operability and polymer sampling. The pilot answered its objectives, but still a lower viscosity than expected was measured in the sampler well. Key deliverables were: • How to operate the whole process chain of viscosified water at topsides level • Better knowledge of polymer degradation from topside to deep into the reservoir • Data required to properly size an extended polymer project.

Polymer Flow Through Porous Media: Numerical Prediction of the Contribution of Slip to the Apparent Viscosity

“…2 yields an order of magnitude forγ eq of 0.5 s −1 . This value is consistent with real oil fields applications (Morel et al 2015). This suggests that, in a significant part of the reservoir, the flow is primarily Newtonian.…”

Mechanical Degradation of Polymers During Injection, Reservoir Propagation and Production - Field Test Results 8 TH Reservoir, Austria

“…To investigate polymer degradation at reservoir flow conditions, polymer samples could be obtained from wells drilled close to an injection well and using downhole sampling (Morel et al 2015). As no well was available for sampling, polymer degradation in the reservoir was assessed by performing laboratory experiments.…”

“…Morel et al 2015). To test if surface polymer solution samples obtained in the field test of the 8 TH reservoir are affected by pumping, a well test was performed.…”

Upscaling Polymer Flooding to Model Sub-gridblock Geological Heterogeneity and Compensate for Numerical Dispersion

“…A larger pilot in the Camelia field was commissioned in February 2010, with the objective of confirming the long term operational feasibility. The pilot was successfully completed in August 2012, injecting 7 million barrels of a 900 ppm polymer through three wells (Morel et al 2015).…”