Brine Mud Pipeline Cleaning

Project Overview

Altrad was asked to clean a 1.8km Brine mud pipeline by Inovyn. The 6” nb pipeline was fouled with a significant quantity of calcium scale (mainly Calcium Carbonate) reducing its internal bore to approx. 3”. As the pipeline is buried under farmland, high pressure water jetting could not be performed because there were not sufficient access points.

The Solution

Chemical cleaning was a viable option to clean the pipeline without the need for extensive excavations. Scale samples were analysed in Altrad’s laboratories to determine the most efficient parameters for cleaning. It was determined that the most efficient method to remove this type of scale is dissolving it in a mineral acid, Hydrochloric Acid was chosen. A successful trial was initially performed at a suitable location, where 100m of the pipeline were cleaned. Following that the whole 1.8 km pipeline was cleaned using inhibited Hydrochloric Acid.

The Process

Two fully bunded pump stations were set up at either side of the pipeline. One side of the pipeline was in the farm fields so the set up was adjusted to ensure each flange joint was placed in a suitable chemical bund to eliminate the risk of contaminating the ground. The area was barriered with temporary heras fence to prevent unauthorised access and labels were posted. Three vent points were identified at high point location along the pipeline and IBCs with alkaline solution were installed so any gases/liquid produced during venting were captured and neutralised.

Before commencing the chemical cleaning, the Environmental Agency audited the set up; the outcome was successful with one minor observation that was rectified by Altrad.

High head centrifugal pumps were used to pump the acid solution from one side to the other several times, topping with acid as required to maintain the decided concentration of acid in the solution. Once the chemical cleaning was completed the pipeline was neutralised using a 0.5% Sodium Carbonate.

The effluent was neutralised and disposed at an EA licensed waste disposal site.

Client Testimonial

“The project was finished on time and to a high standard. Altrad have maintained excellent standards throughout the project”

Philip Hughes, Inovyn

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