Pressure maintenance in oil production pipelines: equipment and simulation

Summarization: The oil production in every well will ultimately decline after some production period and “intense” treatment of the reservoir, the well and/or the surface flowlines will be necessary to maintain the production at an economically viable rate. The oil recovery methods are distinguished in three major categories: primary, secondary and enhanced oil recovery. From the aforementioned categories, only the second involves intervention to the midstream facilities. Pressure maintenance of the multiphase production fluids in the flowlines is a technique, which can be easily implemented in existing installations. It may be implemented either by reducing the pressure with surface chokes and orifice plates or by boosting the pressure with new equipment (pumps and compressors). Two primary factors of the pressure maintenance have to be studied in detail and closely monitored: the flow assurance in the pipeline and the proper sizing and selection of the pressure boosting equipment (pumps and compressors). In this study, a research is conducted on multiphase flow assurance issues and particularly the ones associated with the pressure boosting techniques. Several means of pressure control exist, for example changing the opening frequency and duration of flow valves and surface chokes and installation of orifice plates, but this study focuses on the application of multiphase pumps in line with the production flowlines both onshore and offshore (not inside the well). All major types of production multiphase pumps are presented in detail, together with their operational characteristics. At the last part of the thesis, the performance of a multiphase pump in an oilfield is simulated in order to demonstrate the utility of such novel systems in the oil midstream sector