Review of the API RP 14E erosional velocity equation: Origin, applications, misuses, limitations and alternatives

Abstract

Oil and gas companies apply different methods to limit erosion-corrosion of mild steel lines and equipment during the production of hydrocarbons from underground geological reservoirs. One of the frequently used methods is limiting the flow velocity to a so-called "erosional velocity", below which it is assumed that no erosion-corrosion would occur. Over the last 40 years, the American Petroleum Institute recommended practice 14E (API RP 14E) equation has been used by many operators to estimate the erosional velocity. The API RP 14E equation has become popular because it is simple to apply and requires little in the way of inputs. However, due to a lack of alternatives and its simplicity, the API RP 14E equation has been frequently misused by it being applied to conditions where it is invalid, by simply adjusting the empirical c-factor. Even when used within the specified conditions and associated applications, the API RP 14E equation has some limitations, such as not providing any quantitative guidelines for estimating the erosional velocity in the two most common scenarios found in the field: when solid particles are present in the production fluids and when erosion and corrosion are both involved. A range of alternatives to the API RP 14E equation that are available in the open literature is presented. Some of these alternatives overlap with API RP 14E, while others go beyond its narrow application range, particularly when it comes to erosion by solid particles. A comparison between the experimentally obtained and calculated erosion by different models is presented. The erosional velocity calculated by some of the models was compared with that estimated by the API RP 14E equation.