VERIFYING PRODUCTION LOSSES DUE TO PETROLEUM FLOW IMPROVING WELL INTERVENTION AND DESIGN

摘要

The purpose of this research is to identify in the literature: causes, factors, case study descriptions and adopted solutions for production losses regarding the petroleum flow in offshore oil wells. Those facts will be organized and structured to identify potential zones of intervention for planning the well maintenance during well design phase to avoid production losses. This paper focuses on four offshore regions: Campos Basin, Gulf of Mexico, North Sea, and West Africa. These regions represent the most significant share of offshore oil production in the world. Data set available in the last thirty five years through academic, technical and governmental reports in the literature were the basis of this study. The procedure was accomplished in three steps: (1) data research (2) analysis of the data (3) guidelines establishment. The main cause of production loss regarding the petroleum flow is the solids deposition in the well/line system, such as hydrates, asphaltenes, wax, scales (barium sulfate, strontium sulfate, calcium sulfate, calcium carbonate, and naturally occurrence radioactive material), and calcium naphthenates. In this work the superposition of graphics (hydrate curve, wax appearance temperature, asphaltene onset pressure, and saturation index) resulted in a region free of solids deposition, denominated as "flow assurance envelope". The main expected result is to propose a guideline to be used during the well design phase in order to minimize and facilitate the well intervention. The main contributions of this paper to the oil industry are the identification of potential zones of intervention due to solids deposition in the well/line system, the foresight of well intervention before the beginning of the oilfield production, and finally, possibilities to improve the well or intervention design.