Analysis Of Pressure Distribution Along Pipeline Blockage Based On The Cfd Simulation

Pipeline blockage, which results from solid and hydrocarbon deposition caused by changes in pressure, temperature, or composition, is a critical issue in oil & gas production and transportation systems. Sometimes blockage, which extends several miles in the long-distance pipeline, can be assumed as a new pipe with a smaller diameter. Therefore, it is imperative to detect the location and size of blockage in pipelines more accurately and efficiently to reduce the number of pipeline accidents. This paper explores the distribution of pressure and pressure gradient through the pipeline without/with single blockage under different operating conditions. 3-dimensional (3D) computational fluid dynamic (CFD) simulations under steady state are carried out to examine the effects of blockage location, blockage diameter and blockage length. The orthogonal array testing technique is applied to study the extent to which factor affects the pressure drop most. The dimensionless parameters like dimensionless blockage location, dimensionless blockage diameter, dimensionless blockage length and dimensionless pressure drop, are introduced to evaluate the relationship among the pressure drop and blockage characterizations. Three fitting formulas of dimensionless parameters distribution are proposed and could be used to locate the pipeline blockage and estimate its diameter and length as well. Finally, laboratory experiments were run to validate the blockage prediction model. The fluid frictional apparatus is modified by replacing part of the pipe with a section of small diameter pipe to simulate the actual partial blockade pipeline. The obtained deviations of pressure drop between the lab experiment result and the prediction model is limited to under 30%. Therefore, the deviation should be taken into account while assessing the blockage through the pipeline based on the blockage prediction model, which also allow the operator to assess partial blockage efficiently and economically

Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Applications of aerospace technology to petroleum extraction and reservoir engineering

Through contacts with the petroleum industry, the petroleum service industry, universities and government agencies, important petroleum extraction problems were identified. For each problem, areas of aerospace technology that might aid in its solution were also identified, where possible. Some of the problems were selected for further consideration. Work on these problems led to the formulation of specific concepts as candidate for development. Each concept is addressed to the solution of specific extraction problems and makes use of specific areas of aerospace technology

Analytical modelling of the hydraulic effect of hydrate deposition on transportability and plugging location in subsea gas pipelines.

Accurate prediction of the hydraulic effect of hydrate deposition and plug location is critical to the safety and operability of natural gas transport pipelines, especially for gas-dominant subsea pipelines where maintenance and intervention activities are more difficult. To achieve this, the present work improved an existing two-phase pressure drop relation due to friction, by incorporating the hydrates deposition rate into the equation. In addition, a model has been developed to predict the pipeline plugging time. The transient pressure drop predictions in the present study for all six cases at high and low velocities are within 4% mean relative error. Similar predictions by Di Lorenzo et al. are within 40% maximum relative error, while the mean relative error of the transient pressure drop predictions by Zhang et al. was 7.43%. In addition, the plugging flowtime model underpredicts the plugging time by a mean relative error of 9%

Assessment of CO₂ storage potential of the Wilcox Group in an onshore region of Texas

This study assesses the suitability of the onshore Wilcox Group for carbon dioxide (CO₂) sequestration building on previous extensive studies of oil, gas, and water resources in this interval. I use a multi-stage methodology to down-select sites, estimate CO₂ storage capacity, and evaluate the economic feasibility of a Carbon Capture and Sequestration (CCS) project. Structural, stratigraphic, and sedimentological analysis combine to define structural compartmentalization and sand presence and continuity. The CO₂ injection window is identified beneath the supercritical depth (800m) and the Underground Source of Drinking Water (USDW), and above the overpressure boundary. Reservoir quality analysis, based on cores and well logs, defines the reservoir properties. The results indicate attractive sandy intervals with good continuity (Delta III, III-2, B, and C), with reservoir properties ranging from 0.10 to 0.26 porosity and 5 to 160 mD permeability. The Wilcox geologic study confirms the feasibility of carbon storage. CO₂ storage capacity for selected sites is estimated using EASiTool (GCCC-BEG software), followed by the selection of a case study project area “site A”. The Fayette coal-fired power plant was selected for the economic assessment. Site A's storage capacity ranges from 572 million tonnes (MMT) to 731 MMT, depending on whether closed or open boundary conditions are assumed. Sensitivity analysis indicates a potential 50% variation in mean capacity scenarios. The cost breakdown includes capture at $77.83/tonne, transportation via pipeline at$0.70/tonne, and storage at $5.06/tonne, resulting in a total CCS cost of$82.26/tonne, as estimated by Gaffney Cline’s Cost Assessment Tool. With carbon credits priced at $85/tonne, the project is near break-even for CCS in the AOI. However, there is room for further assessment to explore cost reductions, particularly in industries with lower capture costs. The Wilcox formation offers low and attractive storage costs. These findings provide valuable insights for decision-making in future CCS projects within the area of interest and contribute to a broader understanding of the CO₂ storage potential in the Wilcox Group onshore in Texas.Energy and Earth Resource

Predicting hydrates plugging risk in subsea gas pipeline: CFD, analytical and linear regression modelling.

This study addresses critical limitations in managing hydrate plugging risk for gas pipelines. The main challenges lie in accurately predicting hydrate deposition rates and associated pressure drops. To overcome these limitations, the study developed and validated a 3D computational model using computational fluid dynamics (CFD) and mathematical models. The model simulates a 10-meter long, 0.0204-meter diameter horizontal pipe section. The core of the model employs Eulerian-Eulerian multiphase modeling within ANSYS Fluent software. This approach successfully predicted hydrate deposition rates within a ±10% uncertainty range across various subcooling temperatures and gas velocities. At lower gas velocities (4.7 m/s), the model exhibited significant improvement over existing methods. Compared to a 925.7% deviation from experimental results, the model outperformed an analytical model which underpredicted by 27-33%. Similarly, at higher velocities (8.8 m/s) and varying subcooling temperatures, the CFD model demonstrated high accuracy, with deviations ranging from a slight underprediction (1%) to a moderate overprediction (14%). The study revealed a significant finding related to pipewall shear stress. The model predicted a sequential increase in average shear stress along the pipe at different gas velocities (2 m/s, 4 m/s, 6 m/s, and 8 m/s). These values exceeded 100 Pa, aligning well with established experimental observations. Beyond deposition rates, the CFD model accurately predicted the location, phase changes, and pressure drop profiles during hydrate formation, agglomeration and deposition. This aligns with findings from previous experimental studies. Furthermore, the model achieved a mean relative error of 4%, significantly outperforming models with higher errors. The model for predicting plugging flowtime also yielded valuable results. While it underpredicted plugging time by a mean relative error of 9%, this level of discrepancy is considered acceptable for proactive intervention strategies. The study acknowledges practical limitations and emphasizes the need for field validation of its propositions. Nonetheless, the findings provide valuable insights and pave the way for future research in this domain

New Technologies in the Oil and Gas Industry

Oil and gas are the most important non-renewable sources of energy. Exploring, producing and managing these resources in compliance with HSE standards are challenging tasks. New technologies, workflows and procedures have to be implemented.This book deals with some of these themes and describes some of the advanced technologies related to the oil and gas industry from HSE to field management issues. Some new technologies for geo-modeling, transient well testing and digital rock physics are also introduced. There are many more technical topics to be addressed in future books. This book is aimed at researchers, petroleum engineers, geoscientists and people working within the petroleum industry