Modern in-line inspections can detect shallow dents in pipelines, with depths less than 2% of pipeline diameter. These dents are very common in thin-walled, small diameter refined and multiproduct lines, and frequently coincide with longitudinal welds and girth welds. Traditional dent assessment methods (such as the EPRG approach) can be conservative. Dents can have short predicted fatigue lives, but shallow dents are not known to be a major cause of pipeline failure, unless they are associated with a weld, a gouge, a crack, or severe pressure cycling. The conservatism affects both static failure assessments and fatigue assessments, resulting in high repair rates for shallow dents. This conservatism is partly due to: • Limitations of how the dent shape is modelled in the assessment methods; • Simplifications of the modelling of the stresses range; • Limitations of the calculation of strains in a dent based on inspection measurements; • Inability to model the changing cyclic stress range with changing dent shape. This paper shows that high resolution geometry inspection data contains irregularities which need to be filtered and smoothed. Advanced local regression methods are shown to give effective smoothing by removing errors but retaining the important elements of the real dent shape. The smoothed dent shape is used with the strain estimation methodology given by ASME B31.8 Appendix R, and an appropriate strain limit (based on likely weld quality), to assess whether cracking is likely to have initiated during dent formation. A methodology is then presented, based on Finite Element Analysis (FEA), which improves the accuracy of cyclic stress assessments of shallow smooth dents. The FEA model geometry is provided by the smoothed version of the measured dent shape. The pressure at which the dent shape was measured affects the calculated dent shape and stress as internal pressure varies: this effect is included in the model. The calculated cyclic stresses are used with S-N curves, such as those in BSI PD 5500, to estimate dent fatigue life. This methodology is then applied to 88 dents in two pipelines operated by ExxonMobil in the UK, using detailed high resolution geometrical in-line inspection data, comprehensive pressure cycle measurement data and enhanced dent assessment using the FEA method. It is concluded that this methodology can significantly improve the operator’s pipeline integrity strategy.

A solution for extend run life with no intervention in a high sand cut and high viscous fluid application for La Hocha field (Huila, Colombia) is presented through the installation of Progressing Cavity Pumps (PCP) designed with aggressive geometries including low rotor swept angle and minimum geometry index concepts. This application has 100-300 BFPD flow rate, sand cut up to 40%, 16°API fluid and 850 cp @ 100°F. This document shows the methodology applied in the selection of well candidates with high frequency of interventions due pump failures associated to sand production and well sanded. The effect of the PCP geometry design, cross sectional area, pitch length, helix angle, pump fit, and elastomer were evaluated consistently as selection criteria in order to verify their impact on PCP run life for sand production applications. The document aims to validate the PCP theoretical design principles with the statistic and results gathered from field during the past 3 years in La Hocha field application. The "Fat Boy project" resulted in less intervention, well services, minimizing production delays and associated costs. The project started on mid-2012, due to successful results has been expanded and nowadays represents the 85 percent of the wells in La Hocha field. This is all part of a combined effort looking for reliable and cost-effective solutions for challenging applications. Progressing Cavity Pumps are used in a variety of oil and gas applications where their beneficial characteristics such as positive displacement, high efficiency, low internal shear rates and pulseless flow provide advantages over other artificial lift systems. PC pumps are available in several geometries which determine their suitability for specific applications assuring optimal performance and extended run life.

Pipeline seam welds are often inspected using ultrasonic In-Line Inspection (ILI) technologies. The measurement performance specification of an ultrasonic ILI tool is based on simple, planar, machined notches which are very reproducible, but are not representative of the complex flaw morphologies that occur naturally in seams such as hook cracks and tilted lack of fusion flaws. In order to assess ILI performance on naturally occurring flaws, “in-the-ditch” Nondestructive Testing (ITD NDT) is performed to validate a subset of the population of ILI reported features. Due to the limited number, type, and dimensional (height and length) uncertainty of these flaws, the field validation approach has limitations in terms of efficiency and accuracy in determining ILI detection capabilities and sizing performance. Recently, specialized synthetic flaw fabrication technology has been developed and provides complex, natural crack-like morphologies with reliable and reproducible size dimensions. Effective validation spools with flaws (of representative geometries) can be achieved through engineered designs that consider the number, size and shape of manufactured flaws. This enables owners to quickly and reliably assess the performance of both ILI tools and ITD NDT operators. Assessing performance with the synthetic flaw approach provides results that are more comprehensive and cost-effective compared to the typical field validation approach alone. This is because the flaw population is designed rather than randomly selected from excavation data. This paper addresses the design, use and field experience with validation spools. This paper will present the performance of ILI tools and UT examiners based on synthetic flaw qualification exams, and how this supports related ILI and operator validation work.

The combination of well conditions such as high levels of carbon dioxide (CO2, an average of 15%), 85% water cuts (WC), sand production, and heavy viscous oil is one of the biggest challenges for any artificial lift system (ALS). Progressing cavity pumping (PCP) is the preferred method for sand and heavy oil production; however, CO2 presence in the form of carbonic acid, generates corrosion and pitting on the carbon-steel section of the Progressing Cavity stators. This condition results in short run life for PC pumps with standard materials historically installed. Taking advantage of the corrosion strength properties that Stainless Steel (SS) material has, a new SS PC pumps were manufactured to be installed in highly corrosive application and then determine the increase on run life for those wells previously affected by corrosion. This paper describes a section of the results from the flow assurance improvement plan obtained by the installation of PC pumps with SS technology in terms of workover (WO) intervention savings and extended run life in nine wells operating in Gabon, West Africa. This paper describes the methodology applied in the selection of the PCP models to be manufactured with Stainless Steel technology considering the dimensional restrictions the PCP would have due the casing size of the well completions where the PC pump would be installed, as well as the pump design requirements related to the expected flow rate in the wells historically affected by corrosion. In addition, the paper shows the screening done on the well candidates for the installation of SS PCP, based on historical well intervention data specifically associated to corrosion. Since the installation of the SS PCP technology, the client has performed several acid stimulations that have required pulling the PC pumps out of hole and re-running them multiple times. Throughout these operations, the PCPs have had no failures requiring intervention. The installation of SS technology has improved well run life across all nine candidates by 584% on average. The SS PCP technology continue to run in all nine wells with no corrosion-associated interventions. For an average of 326 days across all nine wells, there have been no WOs performed on the PCPs. The reduction in WOs has helped to avoid production losses, downtime, and associated costs. SS PCP has shown great results extending PC pump run life over 6 times compared to previous applications and has proven to be a good option for larger flow rates in 5.5 in casing completions.