Use of Flexible Data Acquisition on Cleaning Pigs for Offshore Applications
The expanding development of offshore gas and oil reservoirs particularly in deep water areas are extending the challenges for pipeline integrity in design and construction as well as maintenance and inspection. The existing offshore pipeline systems on the other hand are undergoing significant changes in design and/or operating conditions. For example new tie-ins from new wells or massive declining flow rates. Considering the high importance of these systems and the high consequences of pipeline failures, the relevance of pipeline cleaning and inspection is obvious. Therefore a flexible data acquisition system applied with regularly operated cleaning pigs is an valuable intermediate step for pipeline monitoring below the level of In-line Inspection. The Data Logger measures physical values like accelerations (3 directions), absolute and differential pressure and temperature. Design as an add-on for pipeline pigs, it can be used for nearly any type of cleaning tool. The paper describes the basic functions and design of the data acquisition system. Further some examples of real data achieved from offshore runs are presented and the versatile options of the evaluation are discussed. For example it is very interesting how the hydrostatic pressure even in a gas line can indicate the pipeline profile. The value of these information can be increased by the continuous monitoring of the measurements at regular cleaning runs. Opening the possibility to evaluate the development of the achieved data from run to run either by unchanging of varying tool design. Even if single run results are not particularly conspicuous, the difference may contain valuable information.