Saudi Aramco studied such algorithms to produce images simulating the flow inside a pipe’s cross section, possibly reducing the need for separator-based multiphase flowmeters. A former technical manager with Petrobras discusses the development of the company’s flow assurance philosophies and strategies. Looped lines are used to reduce pressure drop and increase flow capacity, but information on the flow behavior or predictive methods are not available for these systems. Bypass pigging has advantages over conventional approaches. Its application to multi-phase flow with high wax content crude is discussed.
At the 2016 Gulf of Mexico Deepwater Technical Symposium in New Orleans, a presentation discussed the application of sensors and analytics in pipeline integrity management systems. An experimental study was conducted by use of a 6-in.-inner-diameter Use of unmanned aerial vehicles to monitor pipeline networks for theft and other issues is discussed. Bypass pigging has advantages over conventional approaches. Its application to multi-phase flow with high wax content crude is discussed.
The startup of a second FPSO will add 115,000 BOPD to the deepwater project offshore Angola, bringing overall production capacity to 230,000 BOPD. Commissioning is complete and Bechtel has turned over care, custody, and control of Train 1 to Cheniere, It's the first liquefaction train placed into operation in a greenfield facility in the lower 48 states. Current production from the phase is 400 MMcf/D and expected to peak at 700 MMcf/D. A third phase also is slated to come on stream this year. McDermott will provide EPC, hookup, and commissioning of the Cassia C topsides, a jacket, and a bridge to link Cassia C with the existing Cassia B platform.
This course will speak to the important phases of commissioning and initial startup of a project. Engineers and operators new to commissioning will learn what the important issues are. Design engineers not involved in commissioning will gain insight into design requirements imposed by commissioning and startup. The initial startup and commissioning phase are integral to successful and cost effective operations. Anyone working in this area should be aware of the most developing issues.
When waxy oil is transported through a pipeline and the pipeline operating temperature drops below the waxappearance temperature (WAT), the wax will precipitate and eventually deposit onto the pipeline's interior surface if a temperature gradient between the bulk fluid and the pipe wall exists. However, because of various operational factors, routine pigging might be delayed for an extended period, thus allowing the wax deposit to accumulate. When this occurs, progressive pigging is required to gradually remove the wax accumulation. Typically, it starts by launching a bore-finding pig (BFP), as shown in Figure 1, followed by pigs with progressively increasing diameters until the routine pig can be fully resumed. An example of a series of progressive pigs and an example of an intermediate cleaning (IC) pig are shown in Figs. 2 and 3, respectively.
Li, Weidong (China Universiyu of Petroleum, Beijing) | Huang, Qiyu (China Universiyu of Petroleum, Beijing) | Wang, Wenda (China Huanqiu Contracting & Engineering Co., Ltd.) | Ren, Yijie (China University of Petroleum, Beijing) | Dong, Xue (China University of Petroleum, Beijing) | Zhao, Qi (China University of Petroleum, Beijing) | Hou, Lei (China University of Petroleum, Beijing)
Widely used as it is, pipeline pigging still holds ambiguities in its mechanisms. In this paper we explore the nature of the wax removal process with a unique pigging facility. Solid wax content, yield stress, viscoelasticity, and microscopic characteristics of wax samples are thoroughly studied with differential-scanning-calorimetry (DSC) trials, rheological tests, and microscopic observations. We found that the relative solid wax content is approximately linearly dependent on temperature, and yield stress can be well-fitted with wax content in an exponential format. An investigation on wax-breaking force indicates that it increases with solid wax content. Wax removal efficiency increases with wax thickness and pipe-wall temperature, decreases with a wax-mixing ratio and solid wax content, and it varies irregularly vs. the scraping-element hardness in the pig. Furthermore, a prediction model of wax removal efficiency was developed on the basis of nondimensional analysis. The absolute average deviation of verification experiments against this model is 5.22%. This model might benefit in estimating the wax-scouring capacity of the wax-in-oil slurry and, therefore, helps to avoid wax blockage and to arrange the pigging program.
Pipeline inline inspection requires a proper cleaning of the pipeline inner walls. In the case hereby described of a 30km 12" offshore line, a significant amount of wax deposits was expected and a series hydromechanical cleaning tools were deployed, after a preliminary series of less aggressive pigs. Normally, the progress of the cleaning process is monitored only by the arrival conditions of the cleaning tools and of the receiving trap. To improve the process, miniaturized pressure, temperature and acceleration sensors were added to the cleaning tools, directly in the field, without any modifications to the cleaning devices and without introducing any additional risks or operating impact. After each instrumented cleaning tool, the sensor data were quickly analyzed and led to the selection of most suitable subsequent tool. In this way, it was observed that the pig conditions and the amount of material collected in the receiving trap did not fully indicate the true cleaning status of the pipeline, while the sensors provided a clearer picture. The pig sequence was thus optimized in number and type of pigs and the intelligent pig run was preformed successfully with no issues or data loss. The advantage of these tiny sensors, not foreseen in the hydro-mechanical pig design, is that they can be applied to almost any pig with minimal-to-no modifications. This information can be used in a number of ways, including detection of flow restrictions (dents, deposits), and can also be used to recreate the line elevation, profile with limited a priori information.
It is well understood that deposits such as corrosion and scale can greatly reduce the flow efficiency and throughput of a transport pipeline system. Regular intervention activities to promote flow assurance such as frequent mechanical pigging, introduction of chemical corrosion inhibitors, and introduction of drag reducing agents all require consistent operational expense, or significant pipeline downtime. Use of interior pipeline coatings and liners are potential long-term solutions which would represent a way to provide long-term refurbishment benefits.
This work describes a novel material designed to interact specifically with highly corroded and weathered pipe, enabling in-place application and refurbishment. The material is applied extremely thinly on the pipeline interior, such that it might be considered a surface treatment, yet it is designed for permanence and for strong adhesion to even severely corroded surfaces. This water-and-oil compatible, chemically resistant material shows extreme resistance to corrosion, particle abrasion and delamination under operational conditions, and is specifically designed to reduce surface roughness by several orders of magnitude. By reducing surface roughness, losses due to frictional drag can be minimized, together with the chance of forming deposits of iron scale and black powder that can constrict pipeline flow and overall production.
A case study is presented in this work which describes application of the coating to a fluid transport system, including a variety of different "challenge" features including: 90° 1.5D bends, valves, weld seams, flanged connections, and heavily corroded surfaces. The pipeline systems were all treated via an in-situ methodology and evaluated for flow performance both through modeling and experimental observation. The study of the practical effects of utilizing a low surface energy, low surface roughness coating that can be effectively applied to severely corroded pipelines with a minimum of surface preparation demonstrates how new material breakthroughs can allow for revitalization of previously mature intervention techniques.