Unique & Practical Approach in Selection and Classification of Hydrocyclone Desander Technology: Utilizing a Decade of Experience

Abstract

Abstract With the advent of advancement in hydrocyclones in oil industry, there has been various types of hydrocyclone based desanding system developed each with its own pros and cons. Main challenges being the handling of multiphase fluid resulting in four phases of feed and challenges in designing. Operators had been facing various challenges in sand management since a decade which has resulted in installation of various hydrocyclone based desanders. Many of the hydrocyclone based desanders did not perform as per expectation and mixed results were observed. With more sand handling issues expected in future, a study was conducted to ascertain lessons learnt and challenges in past installations and way forward for future. A focussed team which includes production technologists and process specialists was established. The team compiled the installation histories of earlier installations and challenges. These included design, operational and logistic details for any installation. Approximately 15 different desander technologies currently prevalent in market and within the region were evaluated to understand the mechanism and variety of each type. The cyclone system was categorized into fixed, changeable with insert and dynamic cyclonic desander for ease of evaluation. The learnings from the earlier installations indicated significance of category which needs to be considered for an installation. Parameters like pressure drop across the cyclone, inlet pressure at the cyclone system, particle size separation, gas volume fraction at the feed volume of sand being produced, sand handling capability of the facility etc. turned out as significant contributors for selection of desanders. Operator's conditions of high gas volumes, relatively finer particles being produced and low pressure environment turned out to be biggest technical challenges in selection of a proper desander. Other challenges included importance of a multi-disciplinary team, contracting strategy and type of desander to be deployed. It was apparent from the study that any future installation would require more systematic approach rather than "pick up from shelf" approach on the desanders. A unique selection flowchart was established as a guideline for selection of hydrocyclone desanders on the basis of major parameters to decide not only on the type of desander required but also the location of desander in a facility. The new by defined category eased out this entire process. To avoid any failure for future selection and installation, a well-defined contracting strategy was established to encompass various types of desanders easing the selection process and utilizing the study results. This entire effort resulted in huge potential value creation and promised a significant saving in man hours.