A reliable strategy for slug flow attenuation in pipeline-riser systems

Adegboyega B Ehinmowo ,E T Evwierhoma ,Aliyu M Aliyu ,Yahaya D Baba

doi:10.1088/1742-6596/1378/4/042103

Abstract

Oil and gas activities across the globe now take place deep offshore. To operate in this harsh environment, there are numerous challenges. These can be in the form of high cost of production, space constraints, operational and technological demands. The co-transportation of oil and gas in same pipeline is one of the operational and technological approaches adopted in the industry to meet the transportation of produced crude. This approach comes with its attendant flow assurance difficulties. Slugging is one of such problems which can constitute operational hitches resulting in production reduction and sometimes eventual plant shutdown. Existing attenuation techniques are limited in various ways. Therefore, seeking a reliable solution to this problem is highly desired.In this study, an experimental study of multiple techniques for slug attenuation was attempted. A passive device-the intermittent slug absorber, topside choking and topside separator were investigated. The results show that a combination of the methods proves to be more effective compared to individual techniques. A significant reduction in riser- base pressure of up to 39% was achieved. This is advantageous and translates to an increase in oil recovery. Thus, the proposed strategy helps to achieve system stability and improved production at a lower cost.

Highlights

Flow assurance in petroleum production systems is of immense importance
Bifurcation maps were developed for slug flow conditions using topside choke and separator gas outlet valves to study the attenuation capability of the device and the separator and their combined operation modes
It is desired to have the slug flow stabilized at low pressure and large valve opening

Summary

Introduction

Flow assurance in petroleum production systems is of immense importance. The operators desire economical, environmentally safe, and continuous flow of oil and gas. One of the flow assurance difficulties facing producers is slugging. This is an alternating flow of oil and gas characterised by pressure and flow fluctuation. This intermittence could result in a number of operational problems including topside separator’s trip and eventual shutdown. Existing efforts to curb this menace have either have limited applicability or negatively impact production [1,2,3]. There is a continual search of techniques for its control and attenuation

Objectives

Methods

Results

Conclusion