Bridging the Gap between Benchtop Testing and Field Conditions in Flow Assurance Studies

Abstract

Objectives/Scope: The goal for any flow assurance study is to capture the thermo-hydraulic conditions in flowlines without having large scale flow facilities that closely represent the field. As such, benchtop testing must as best as possible reproduce the shear and dispersion of the phases encountered in flowlines. With the increasing need of laboratory testing for solid precipitation and production chemicals, coupled with reduced CAPEX and OPEX, it is critically important to have a robust benchtop testing system that give reliable and transferable data that can be used for field applications. Methods, Procedures, Process: While many benchtop tools are widespread (e.g., autoclave cells, rocking cells, cold fingers) and are used extensively by industry, there is still a significant gap in bridging the results from these lab scale devices to field conditions. One of the major concerns with the current testing rigs is the inability to reproduce the shear AND phases dispersion that are present in pipe flow and are a consequence of the multiphase flow conditions. To bridge the gap between benchtop testing and filed conditions, we demonstrate how an innovative testing rig, called rock-flow cell, can be used to capture flow assurance issues (e.g., hydrate, wax, asphaltene, scale, corrosion, sand transport) under pseudo-flow conditions. Results, Observations, Conclusions: This system is superior to existing testing systems due to its ability to reproduce flow conditions that are typically found in actual production flowlines, such as, stratified flow, stratified wavy flow, and slug flow. In addition, the system is compact and inexpensive to build and operate, unlike flow loop systems, which are currently the only reliable testing rig with proper flow conditions. Novel/Additive Information: The rock-flow cell can be easily used for testing of chemicals (e.g., anti-agglomerants and kinetic inhibitors) for hydrate management, for assessing wax deposition of crude oils, for testing of scale precipitation, and for testing of sand transport; each of these flow assurance issues can be tested separated or combined as desired. Moreover, the rock-flow cell is also a suitable setup for testing of steady-state and transient (shut-in/restart) conditions typically encountered in flow assurance with proper account of liquid loading, water cut, and GOR.