Intra-field pipelines is the most critical constituent of pipeline network used by subsoil users in Khanty-Mansiisk Autonomous District-Yugra. Total length of pressure pipelines in TNK-BP spans 2,965 kilometers: 9% of the total web is corrosion-resistant whereas remaining 2,706 kilometers in operation are not protected against corrosion. Average life of a pipeline is 12 years. A pipeline break, if occurs, may not only drive to shut-down of a field but also have serious technogenic and environmental implications. The Company has developed and put in place a prioritization program, which classifies this group of pipelines as critical. According to the program, these pipelines require time and efforts to assure integrity and longer service life.
The goal is to develop and implement a technology of intra-field pipeline inhibition with the use of batching pigs. This goal sets the following objectives.
Assess operational and economic efficiency of the existing and proposed intra-field pipeline inhibition technologies;
Select corrosion inhibitor with adequate properties;
Develop Instruction Pigging and Inhibition of Pressure Oil Pipeline between DNS-24 and KSP-1 4 using Batching Pigs
Develop an operational procedure for pressure oil pipeline DNS-24 - KSP-14;
Run field trials of the proposed technology in the pressure oil pipeline between DNS-24 and KSP-14, OJSC TNK-Nizhnevartovsk.
There are two (2) inhibition methods in use in the Company: continuous dozing and shock treatment. When inhibiting lengthy pipelines, these two technologies have shown their major week point - inhibitor is difficult to deliver to the cleaned metal surface that consequently leads to the small probability of generating a reliable protective film. The proposed system ties together two existing technologies extending pipeline service life: pipeline pigging and inhibition.
This technology represents a set of below successive operations:
launching of a solid pig;
injection of calculated volume of corrosion inhibitor during specific time set in the Instruction;
launching of a polyurethane foam pig to tail.
The proposed inhibition technology with the use of batching pigs allows coating of pigged metal surface with inhibition film (?? 39–23-1082–84). As records state, cleaned metal surface coated with strong inhibitor solution increases inhibition effect by 15–20%.