American Petroleum Institute

Recommended Practice for Field Analysis of Crude Oil Samples Containing from Two to Fifty Percent Water by Volume - FIRST EDITION; Effective February 1, 2008
 N RP 87

Annotation

The purpose of this document is to provide the user with recommended ‘field' methods of sampling, sample handling and analysis for high water content streams up to 50 % water on a volumetric basis. In particular, this RP was developed giving consideration to offshore installations (both floating and fixed platforms). These installations are generally subject to motion and vibrations, have minimal laboratory equipment, and perform S&W analysis with multiskilled operations personnel as opposed to laboratory chemists. The techniques described, however, are also applicable to onshore locations.

This document provides design and operating guidelines for sampling, sample handling and sample analysis of high water content streams, up to 50 % water by volume. As a guide, this RP targets a relative accuracy of 5 % of reading up to a maximum of 50 % water content as a qualifier for the various methods described herein. For example, the corresponding absolute accuracy for a 10 % water content stream is ± 0.5 % and for 20 % water content is ± 1.0 %.

This recommended practice may involve hazardous materials, operations, and equipment. This RP does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this RP to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

The laboratory testing contained within this RP (see Annex A) is based on a single laboratory—single operator set of results. As with other API standards for field S&W determination methods, no precision and bias calculation was performed and therefore, no inter-laboratory or round robin style testing was performed. The results of the testing of the various methods are primarily intended to provide a general comparison between different methods to facilitate operational choices.