This study analyzes the effects that a bio-inspired blade shape has on the size and structure of a tip vortex. The blade prototype was selected based on the analysis of various insect orders with the purpose of finding wing profiles most suitable for the design of small rotorcraft propellers. Flow simulations are conducted around the bio-inspired blade and in its near wake using commercial CFD software Star-CCM+. Results are compared with those for a rectangular blade. A vortical structure is captured downstream of both blades. Flow data related to these structures is used to show that the bio-inspired shape produces weaker vortices, making it more desirable for rotorcraft implementation.

OpenFOAM is an attractive Computational Fluid Dynamics solver for evaluating new turbulence models due to the open-source nature and the suite of existing standard model implementations. Before interpreting results obtained with a new turbulence model, a baseline for performance of the OpenFOAM solver and existing models is required. In the current study, we assess the accuracy of simulation results obtained with standard models for the Reynolds-averaged Navier-Stokes equations implemented in the OpenFOAM incompressible solver. Two planar (two-dimensional mean flow) benchmark cases generated by the AIAA turbulence Model Benchmarking Working Group are considered: the boundary layer on a zero-pressure-gradient flat plate and a bump-in-channel flow. OpenFOAM results are compared with the NASA CFD codes CFL3D and FUN3D. Sensitivity of simulation results to the grid refinement, linear pressure solvers, compressibility effects, and model implementation are analyzed. Testing is conducted using standard Spalart-Allmaras one-equation, Wilcox's 2006 version of the two-equation k-ω, and SST 1994 turbulence models. Simulations using wall-resolved (low Reynolds number) formulations are considered.

The Oil and Gas industry in recent years have been a great challenge for operators and aervice companies as well. This situation resulted in great opportunities to find efficiencies that can enhancement production, avoid down times and optimize operation in Electric Submersible Pump Systems (ESP). Keeping this on mind, one of the main drivers is implement procedures that can extent ESP run life, and one of the key challenges is to identify any trouble that can impact ESP performance timely so it can implement solutions to avoid failures. The main objective was to develop a troubleshooting manual that could be used for any engineer to identify likely conditions that could be affecting negatively ESP performance and to implement solutions to minimize failure or damage beyond repair in ESP equipment. A jointly team composed by the operator and the service company developed a troubleshooting manual to the proper identification of likely conditions that could be impacting the production and performance of ESP systems. This was achieved using monitoring information, tear down evidence, setting configuration and building a database with all the information in order to group similar cases to identify the best ways to respond to any anomaly in ESP behavior. This procedure was implemented in the field that have an average of 450 active wells with 93% being ESP systems, by socializing it with all the parties that participate in ESP troubleshooting to guarantee a proper handling of any occurrence. The main purpose of the creation of this procedure was to avoid failures associated with ESP operation conditions that could result in early failure; this is measured with the Failure Index (IF) that means the number of average interventions in an ESP field related to the average number of active wells in the same period. The implementation resulted in awareness in all the personnel that when best practices are followed there are better chances of field KPI improvements and savings, in this case the Failure Index of the field was reduced from 0.4 to 0.18 attributed to technology and best practices implementation as well. This paper aims to present the most relevant analyzed cases, the procedures implemented and the results in FI after implementation as well of recommendations to any party interested in implement similar projects in their operations.

No abstract

Electrical failures of the Electric Submersible Pumping ESP systems reached a record high in various Northern fields in 2014. A study was undertaken to identify and understand these failures and their root causes. The analysis revealed that the main cause of the system failure was either the power cable or the motor lead extension (MLE). Through continued developments in technology, the components of the ESPs have been upgraded to increase their performance, efficiency, and run life. In Llanos Norte operation, located in east Colombia, an increase in power cable failures was observed between 2012 and 2014. Those failures represented 50% of the total failures associated with downhole equipment with an average run life of 300 days and the main cause was mechanical damage to the cable sustained during installation. After a detailed well-to-well analysis to identify fault patterns, different reasons arose such as well tortuosity, high run-in-hole speed, changes in cable specifications and deformations caused by the accessories used to protect the cable. All of these items resulted in mechanical damage to the outer armor of the cable, exposing the insulation system to well fluid, which caused an increase in infant (less than 30 days of operation) and premature (less than 365 days of operation) failures. As an immediate action plan, a decision tree was created to determine run-in-hole speed according to different factors such as: well deviation, outside diameter of equipment and the internal diameter of casing; supporting the analysis with calculations of torque and drag. There were also additional actions implemented to reduce cable failures such as: changes in cable specifications (thicker armor and geometry), training the personnel involved in ESP installation (rig and ESP vendor), changes in the tools used for cable handling, use of new accessories for cable protection and upgrading power cables with lead jackets for applications in gassy wells. This paper presents a summary of the different solutions implemented after a thorough analysis carried out with an interdisciplinary team composed by personnel of the Field Operator and ESP vendors. The implementations of all actions represented almost MMUSD$ 4 in savings in three years over a population of 395 wells.