Hydrate Inhibition in the Niger Delta Using Plant Polymer as a Local Kinetic Hydrate Inhibitor

Abstract

Offshore production activities have increased in the Niger Delta region of Nigeria due to available technology to produce petroleum fluids from reservoirs that lie thousands of feet below the waterbed. However, Offshore production in Nigeria is still being plagued by flow assurance challenges such as hydrate formation. In this study, the effect of Niger delta seawater salinity on hydrate prevention is evaluated. The efficiency of a locally sourced kinetic hydrate inhibitor (KHI) is also assessed. The experimental study was conducted in a 12-meter horizontal hydrate flow loop designed to model a horizontal subsea flowline. A sample of Niger delta seawater and compressed natural gas were used as the hydrate formers, and the loop was conditioned to hydrate formation conditions. Although the salinity of the seawater was 26.18ppt, hydrates still formed in the loop, as indicated by a rise in temperature and a rapid decline in loop pressure. Further experiments were conducted using the plant polymer with concentrations varying from 0.01wt% to 0.1wt%. The optimum concentration of the polymer was found to be 0.03wt%. Seawater salinity is not sufficient in preventing hydrate formation in the Niger Delta region. Operators should plan to use KHI to enhance the inhibitive property of the seawater and formation water. The optimum dosage of inhibitor should be used to minimise production cost.