Flow Assurance Problems Research Articles

Development of an Analytical Tool for the Design of Deep Water Riser/Flow Line Thermal Insulation Systems

The offshore oil and gas industry is predicting the discovery of more and more deep water reservoirs. Increased water depths create a requirement for reliable pipelines to economically recover these deep water fields and also to minimize flow assurance problems. Increased flow assurance problems in deeper waters increase the need for thermally insulated pipelines. In this paper we present an overview of the key issues in the analysis and design of thermal insulation systems, identify and discuss how these are addressed by the design tools developed within the DeFRIS project and present results used to validate the algorithms incorporated into the design tool.

A changing hydrate paradigm—from apprehension to avoidance to risk management

Deepwater flow assurance is a major technical concern in the energy industry. Hydrates are the leading deepwater flow assurance problem, by an order of magnitude. Upon initial discovery of hydrate blockages in pipelines there was apprehension, based upon lack of knowledge. Over the last 70 years, development of phase equilibria has provided an acceptable hydrate avoidance ability. However, phase equilibria alone has some limitations. In a growing number of situations for preventing hydrate blockages, risk management is more economical than avoidance. In order to move from avoidance to risk management it is essential to quantify hydrate formation kinetics. That is, avoidance is enabled by thermodynamics, but risk management is enabled by kinetics. These transitions and the state-of-the-art in hydrate kinetics are presented, with challenges for the future.

A Practical Method for Anticipating Asphaltene Problems

Summary Asphaltenes can separate from some oils during depressurization. In other cases, the addition of lift or injection gas can destabilize asphaltenes. This paper presents an integrated approach to predicting all these potential asphaltene problems. Laboratory characterization of asphaltene stability in stock-tank-oil samples is used in combination with standard pressure/volume/temperature (PVT) and compositional data. Details of the characterization technique and prediction method are provided for problems of practical interest, especially for offshore developments where advance planning is of particular importance for many flow-assurance problems. Predictions of asphaltene stability with this approach are compared with live-oil measurements and field experience, where available.