Produced Water Management – An Integrated Approach

Abstract

Produced Water Management – an Integrated Approach

The cost effective management of oilfield produced waters requires the successful integration of a great many activities and skills. Many of those skills, such as Production Chemistry, Corrosion Engineering and Microbiology, are becoming increasingly rare both in oil companies and in their “outsource” service companies. It is hoped that this paper may help address the problems which may arise from these skill shortages by identifying the key factors to consider in any project, and discussing some of topical interest.

Typical problems include above limit oil-in-water concentrations which require cut-backs or no increases in oil production rates, and high downtime due to corrosion, scale blockages, etc, with extremely high costs ensuing from lost oil production.

Information Sources

In general, the oil industry has lost a great amount of expertise over the past 10 years or so, due to “downsizing”, ‘rightsizing’ or whatever the current fashionable term is for cost-cutting lay-offs.

To overcome the resultant knowledge-deficit new sources of information must be accessed and used intelligently. The worldwide web/internet, and company intranets, are sources of a vast amount of information, and much of it is good quality and useful - especially industry-specific sources such as the Society of Petroleum Engineers and relevant vendor websites. However help is still often required from experienced persons to select relevant valid material ‘from the irrelevant or incorrect.

Many publications of particular relevance to the subject of oilfield water management are available from a variety of sources [1 to 7], and those which are standards, e.g. ASTM, are often downloadable from their website, for a fee of course.

In addition to those sources, valuable information may be obtained from commercial conferences or training courses. Often these seem very expensive, per head, and so are often early targets for cost cutting when budgets are under pressure. Of course one can argue that the expenditure of a £1000 or so may be paid back very quickly if it saves only a few days labour spent needlessly in a search for information elsewhere, or many £ thousands/millions if it saves on significant design, capital or operating expenditures.

Given the increasingly apparent lack of relevant knowledge in our industry, we need to increase our commitment to training in many forms, perhaps beginning with providing more assistance to our universities and schools to promote science and technology. Some institutions, e.g. the Institution of Chemical Engineers, do actively encourage their members to spend time in schools to this end, but more needs to be done if we, in general industry in the UK and especially in our oil industry, are not to suffer from a lack of even basic scientific and technical knowledge. Unfortunately, arguably, the teaching of science in our schools has been degraded over many years with chemistry and physics often replaced by environmental science in which teachers promote the over-simplistic view that our future energy needs can be met by building more and more wind turbines – built offshore or in remote locations – but only operating for 30% of the time, or by “the hydrogen economy”, not realising that this requires electricity to be generated initially by nuclear power, if fossil fuels are to be restricted because of C02 emissions.

Education is a cornerstone of an integrated approach to any problem, be it in the oil industry or elsewhere, and this is relevant to produced water management in more than one way. Firstly, produced water disposal is a significant environmental issue, and, secondly, its management requires understanding of a great many “disciplines”, e g. geochemistry (water, oil, rock), reservoir engineering, process engineering, environmental science, oceanography, corrosion engineering and materials science, health and safety, instrumentation, and so on. This is not to say that all we need are people with some science in their education, as other disciplines also play an essential part in any project, e.g. accountants, personnel managers, lawyers, etc.