Rotary Cyclone Will Improve Oily Water Treatment And Reduce Space Requirement/Weight On Offshore Platforms

Abstract

Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper was presented. Publication elsewhere is usually granted upon request provided proper credit is made. Abstract A rotary hydrocyclone was developed for the treatment of the produced oily water on offshore platforms The main advantages of this type of equipment consist in :a few second residence time resulting in a dramatic reduction in weight and volume.higher efficiency when comparing with conventional settling tanks or static cyclones,insensitivity to the platform motion,large flexibility in flow rate and in oil concentration in the treated water,low pressure drop requirement,easily adaptable to changing field operating conditions,modular conception facilitating the offshore installation,reduced maintenance and power consumption resulting in a low operating cost. This paper outlines the results of laboratory work conducted initially on a static hydrocyclone and on a rotary cyclone scale model, with the reasons for the differences in performance of the both type of equipment. A field test of a 2 × 25 m3/h industrial rotary cyclone skid is presented and the field performance analysed Finally main features of the industrial units are presented and a comparison treatment is made. Introduction Equipment installed on offshore platforms for treatment of oily production water in accordance with international standards for discharge of waste effluents are in the majority of cases derived from processes applied onshore : they are heavy and bulky and account for a large share of offshore development costs. In 1984, TOTAL CFP and NEYRTEC decided to work together to develop, with the financial support of the Commission of the European Communities, new methods for de-oiling water produced with crude oil in order to reduce the weight and overall dimensions of equipment embarked offshore. Amongst the processes studied, the "cyclone" route offered the most promise. The research work undertaken had led to the development of a rotary cyclone enabling the weight and overall dimensions to be reduced by a factor of 10 to 20 compared to conventional equipment, whilst at the same time enhancing the de-oiling performance MEASURING FACILITIES AND METHODOLOGY The rotary cyclone was developed on the NEYRTEC petroleum test loop in Grenoble Built to explosive atmosphere safety standards, this loop enables industrial components for expanding, pumping, mixing or separating polyphasic fluids to be tested or qualified under their actual operating conditions with petroleum products. The general configuration of the test loop is shown in figure 1. The following are the main characteristics of the various circuits - Water circuit * industrial saline water : from 0 up to 250 g/l, * temperature : 10 to 70C, * maximum flow : 40 m3/h, * maximum pressure : 15 bars.