Zhou W.,University of Western Ontario |
Nessim M.A.,C FER Technologies
Journal of Pressure Vessel Technology, Transactions of the ASME | Year: 2011
The optimal design level for onshore natural gas pipelines was explored through a hypothetical example, whereby the pipe wall thickness was assumed to be the sole design parameter. The probability distributions of the life-cycle costs of various candidate designs for the example pipeline were obtained using Monte-Carlo simulation. The life-cycle cost included the cost of failure due to equipment impact and external corrosion, and the cost of periodic maintenance actions for external corrosion. The cost of failure included both the cost of fatality and injury as well as the cost of property damage and value of lost product. The minimum expected life-cycle cost criterion and stochastic dominance rules were employed to determine the optimal design level. The allowable societal risk level was considered as a constraint in the optimal design selection. It was found that the Canadian Standard Association design leads to the minimum expected life-cycle cost and satisfies the allowable societal risk constraint as well. A set of optimal designs for a risk-averse decision maker was identified using the stochastic dominance rules. Both the ASME and CSA designs belong to the optimal design set and meet the allowable societal risk constraint. © 2011 American Society of Mechanical Engineers.
Skoczylas P.,C FER Technologies
Society of Petroleum Engineers - 2014 SPE Artificial Lift Conference - North America | Year: 2014
Drive string (rod string) fatigue failures may occur occasionally in Progressing Cavity Pump (PCP) applications. In a deviated well, the drive string is subjected to rotating bending while the pump is in operation. For each rotation of the string, each portion of the rod's surface undergoes a load cycle of compression and tension. This load cycle is overlaid on the approximately constant torque and axial load that are usually the primary loads considered in sizing a drive string. While the alternating load from rotating bending typically results in a small stress compared to the other loads, it can eventually lead to a fatigue failure. This paper presents a model for estimating the life of a drive string before a fatigue failure occurs. This model considers the overall stress state in the drive string, the effects of curvature magnification (which occurs near the larger diameter connections in a coupled drive string), and environmental factors. The model has been developed only for solid rod bodies (whether coupled or continuous), and it is not applicable to hollow rods. This paper also discusses several aspects of lab testing for determining fatigue life. Simple fatigue tests are typically performed under either pure rotating bending, or cyclic bending (without rotation). These tests may not give results that are representative of the actual fatigue life that may result from operation in a different stress state (i.e. when constant torsional and axial stresses are added to the cyclic bending stress). This paper is aimed at assisting production engineers in designing drive strings for applications in which fatigue failures may occur.
Chen Q.,C FER Technologies
Proceedings of the International Offshore and Polar Engineering Conference | Year: 2014
Structural analysis methods used in the design of buried pipelines for the discontinuous permafrost regions need to handle the unique conditions that can arise; in particular thaw subsidence and frost heave. As a chilled gas pipeline traverses from a frost stable soil zone to a frost susceptible zone, frost bulbs are formed around the pipe and cause the pipeline to heave. If there is significant differential heave, pipe bending across the interface between these two zones could result in pipe strains exceeding design limits, or in extreme cases, buckling or tensile fracture. For pipelines subjected to geotechnical hazards, characterization of strain demand is an integral part of the strain-based design process. This paper describes a simplified finite element model that was developed to predict compressive and tensile strain demand of gas pipelines subjected to frost heave. By using features that are typically available in general-purpose finite element analysis software, the proposed pipe-soil interaction model addressed issues that are essential for predicting pipeline strain demand. These issues include pressure-dependent heave displacement, and geometrically non-linear load-displacement response of steel pipe. The simplified model was validated by comparing model predictions to the Caen tests. Copyright © 2014 by the International Society of Offshore and Polar Engineers (ISOPE).
Xie J.,C FER Technologies
Society of Petroleum Engineers - SPE Thermal Well Integrity and Design Symposium | Year: 2015
To recover heavy oil and bitumen from the highly unconsolidated reservoirs of the Western Canada oilsands fields using the horizontal well method, and in particular the thermal in situ method of Steam Assisted Gravity Drainage (SAGD), some forms of sand control, such as slotted liners and wire-wrapped screens (WWS), are generally required to limit sand production and maintain well productivity. Over the past two decades, a number experimental and analytical studies have been performed for developing industry guidelines and best practices for the structural and hydraulic design and evaluation of sand control liners under the challenging conditions of SAGD steam injection and production wells. The vast majority of SAGD applications, estimated at about 90% (RPS 2009), employ slotted liners as the sand control method. Design efforts to address the structural and serviceability requirements, however, often oppose one other, presenting significant challenges to the design of slotted liners. For example, in order to maintain sufficient torque, collapse and strain-absorbing capacities, traditional slotted liners are often designed to have low Open Flow Areas (OFA) around 1%, although a larger OFA is desired for production efficiency. This paper reviews current design requirements for SAGD wells, as well as puts forward a new slotted liner design consideration for the optimized performance under installation and operational loads. Using Finite Element Analysis (FEA) modeling, the effect of key design parameters, such as slot length and slot pattern, are studied. This paper focuses on the feasibility study of achieving higher OFA than the currently-used limit, while maintaining sufficient torque, collapse and strain-absorbing capacities under thermal well load conditions. Copyright 2015, Society of Petroleum Engineers.
Koduru S.D.,C FER Technologies
12th International Conference on Applications of Statistics and Probability in Civil Engineering, ICASP 2015 | Year: 2015
Practical applications for separation of aleatory and epistemic uncertainties are demonstrated with two examples applied to steel structures and pipelines. These examples show the need for separation of uncertainties, the application of existing strategies and their limitations. The first example pertains to the behaviour of a simple steel connection subjected to combined axial, shear and moment loading. Uncertainties in the material properties of the connection components are shown to have a significant influence on the model uncertainty corresponding to the connection moment capacity. The second example shows that the uncertainties in the geometric imperfections of a steel pipeline contribute to the total model uncertainty in the strain capacity of the pipe. More such case studies demonstrating the utility of separation of epistemic uncertainty are expected to lead to increased efficiency in future model development.
Tao G.,C FER Technologies
Society of Petroleum Engineers - SPE Canada Heavy Oil Technical Conference | Year: 2016
Horizontal wells have been widely used to significantly increase reservoir exposure in a wide range of conventional and unconventional oil and gas recovery applications, including tight-rock and multi-stage fracturing, offshore, primary and thermal heavy oil projects. In the heavy oil and bitumen reservoirs of the Western Canadian basin, horizontal wells have been extensively employed in Steam Assisted Gravity Drainage (SAGD) and Cyclic Steam Stimulation (CSS) in-situ recovery projects. In SAGD applications, the lateral sections of these horizontal wells are generally completed with various types of sand control systems, including slotted liners, Wire Wrapped Screens (WWS) and premium screens with a growing percentage incorporating some form of downhole injection or production Flow Control Devices (FCD). Given the relatively shallow depths, low reservoir pressures and high fluid rates of these applications, these horizontal wells are often constructed with relatively high build rates and large diameter tubulars. In an effort to improve project economics, well designs with increasingly longer lateral sections are being pursued. In an effort to reduce potential damage during installation, engineering assessments are commonly conducted to ensure that the structural capacity of these liners exceeds the demand of the combined installation loads caused by liner-wellbore interaction and liner string buoyant weight, often with consideration of a suitable safety margin. To date, given the number of influential parameters, the complex nature of the analysis and corresponding computational demands, methods which employ significant simplifications, such as soft-string torque and drag (T&D) models, have been commonly used to assess liner installation loads. In addition, it appears that the current commercial soft- and stiff-string T&D analysis tools do not consider the nonlinear load capacity envelopes of the sand control liners in the evaluation to assess the potential damage under combined loading during installation. Advanced numerical methods, such as Finite Element Analysis (FEA), have also rarely been employed to evaluate the liner installation loads due to the complex nature of this problem. This paper presents an advanced stiff-string T&D analysis approach developed using the commercial FEA program Abaqus. To demonstrate the application of this approach, several example cases are presented simulating the installation of the slotted liner design into a horizontal SAGD well. In these T&D analyses, wellbore and tubulars were modeled using pipe elements which accurately capture various geometric parameters and associated mechanical responses of the tubulars. Contact interaction and the clearances between the tubulars and the wellbore were modeled. Different friction factor (FF) values were assigned to the cased and open hole sections of the well. By incorporating the load capacity envelopes of the specific slotted liner design into the analysis, this paper demonstrates how this methodology may be applied to assess the load responses and potential damage risks associated with running large diameter liners into high build rate extended-reach horizontal wells. The approach presented in this paper may be expanded to various tubular, completion equipment and drill string running applications. Copyright 2016, Society of Petroleum Engineers.
Alhanati F.,C FER Technologies
Society of Petroleum Engineers - Progressing Cavity Pumps Conference 2010 | Year: 2010
When performing statistical analyses on PCP run-life data, one can easily reach incorrect conclusions if subtle but important issues are not fully understood. This paper illustrates some of these issues using examples from analysis work conducted recently with a relatively large and complete set of data collected from several large operators. Issues examined include misinterpretation of single-variable correlation results and run-life measures. It is impractical to design and conduct lab or field experiments to investigate the effect of individual variables on PCP run-life. On the other hand, with normal field data, it can be difficult to isolate the effects of individual variables. The assumption of "all else being equal" rarely applies to field data. Additionally, different run-life measures can give different results at different times in the life of a field, even when the underlying system reliability has not changed. Awareness of these issues is essential to all companies that collect and analyze PCP failure and run-life information for the purpose of evaluating and improving PCP system performance. Copyright 2010, Society of Petroleum Engineers.
C FER Technologies | Date: 2012-01-17
C FER Technologies | Date: 2011-06-28
computer software for the detection, description, and analysis of deformations in pipes, tubes and casings used in the oil and gas industries.
C FER Technologies | Date: 2016-12-06
Computer software for viewing, analyzing, and manipulating well logs used in the oil and gas industries.