Challenges, Requirements and Advances for Distributed Fiber Optic Sensors in SURF Structures and Subsea Well Monitoring

Author(s):  
Fabien Ravet ◽  
Etienne Rochat ◽  
Marc Niklès

During the past 10 years, the oil and gas industry has gained confidence in the capabilities and the reliability of Fiber Optic Distributed Sensing (OFDS). Real world implementation can be found in both downstream and upstream branches. For example, at one end of the industry spectrum, service companies have started to use Distributed Temperature Sensing (DTS) for in-well temperature monitoring to optimize oil recovery processes. At the other end, pipeline operators have installed pipeline integrity monitoring systems based on Distributed Temperature and Strain sensing (DITEST) to fulfill realtime monitoring of soil stability, pipeline 3D deformation and leak detection. The use of OFDS for offshore structure integrity monitoring such as flow lines, risers and umbilicals has been qualified and field tested already whereas other applications such as performance rating of power umbilicals and enhanced flow assurance system using OFDS are being evaluated. Currently, the offshore full scale implementation of OFDS technologies still faces challenges of its own. In particular, sensor integration into the structure to be monitored is a minimum requirement which applies to any OFDS. If fiber optic is a common mean of data transmission, subsea conditions imply the use of specific components such as Wet Mate Connectors (WMC) and Fiber Optic Rotary Joints (FORJ). These components present large insertion and return loss characteristics for which OFDS require special attention to the OFDS system to comply with such characteristics. The effect of these components is twofold. First it impacts the sensor optical budget limiting its measurement range. Second, sensor sections remain completely blind due to the high reflection levels leaving the structure without status information over distances that can be as large as several kilometers. The present works describes how the DITEST based on Stimulated Brillouin Scattering (SBS) can overcome the limitations imposed by both WMC and FORJ components and fully comply with SURF monitoring requirements. The ability of the DITEST is justified theoretically and demonstrated experimentally through qualification trials involving hotspot detection while WMC and FORJ are part of the sensor path. Their effects are quantified through the determination of the measurement dead zone (shorter than 4m), the temperature uncertainty and the resolution. The work also reports the subsequent installation on operational structures as these trials were successful. The DITEST has been installed to continuously monitor the temperature of a 3km long power umbilical and control the heating system of subsea rigid flowlines whose length can be as large a 45km.

2021 ◽  
Author(s):  
Abdulaziz Al-Qasim ◽  
Sharidah Alabduh ◽  
Muhannad Alabdullateef ◽  
Mutaz Alsubhi

Abstract Fiber-optic sensing (FOS) technology is gradually becoming a pervasive tool in the monitoring and surveillance toolkit for reservoir engineers. Traditionally, sensing with fiber optic technology in the form of distributed temperature sensing (DTS) or distributed acoustic sensing (DAS), and most recently distributed strain sensing (DSS), distributed flow sensing (DFS) and distributed pressure sensing (DPS) were done with the fiber being permanently clamped either behind the casing or production tubing. Distributed chemical sensing (DCS) is still in the development phase. The emergence of the composite carbon-rod (CCR) system that can be easily deployed in and out of a well, similar to wireline logging, has opened up a vista of possibilities to obtain many FOS measurements in any well without prior fiber-optic installation. Currently, combinations of distributed FOS data are being used for injection management, well integrity monitoring, well stimulation and production performance optimization, thermal recovery management, etc. Is it possible to integrate many of the distributed FOS measurements in the CCR or a hybrid combination with wireline to obtain multiple measurements with one FOS cable? Each one of FOS has its own use to get certain data, or combination of FOS can be used to make a further interpretation. This paper reviews the state of the art of the FOS technology and the gamut of current different applications of FOS data in the oil and gas (upstream) industry. We present some results of traditional FOS measurements for well integrity monitoring, assessing production and injection flow profile, cross flow behind casing, etc. We propose some nontraditional applications of the technology and suggest a few ways through. Which the technology can be deployed for obtaining some key reservoir description and dynamics data for reservoir performance optimization.


2021 ◽  
Author(s):  
Defei Chen ◽  
Kun Huang ◽  
Xiangjuan Meng ◽  
Ju Liu ◽  
Bao Zhang ◽  
...  

Abstract Gas injection has become an important means of enhancing oil recovery (EOR) in clastic reservoirs, the Donghe Oilfield, Tarim, has been undergoing gas injection to enhanced oil recovery. During the gas injection, dynamic justification of gas injection was the most severe challenges, which needed to monitor the pressure profile, temperature profile and gas injection profile. Therefore, monitoring gas injection profile has becoming an important part of gas drive reservoirs. Donghe Oilfield was characterized by ultra-deep (>6000m), high temperature (>140°C) and high content of carbon dioxide, conventional manometer and thermometer cannot meet the downhole condition of ultra-deep and high temperature. To continuously monitor gas injection well, permanent fibre-optic surveillance technique featured with outstanding conformance, nice corrosion resistance and long-life span was developed, and a program was developed to use real-time fiber-optic Distributed Temperature Sensing (DTS) and Distributed Acoustic sensing (DAS) to identify the gas injection profile (gas channeling). Monitoring principle and system assembly of the fibre-optic was demonstrated in detail, the DTS utilized Joule - Thompson cooling principle as the gas injected into formation through screen pipe, while the DAS captured the amplitude and frequency of acoustics from the gas flow. DTS and DAS data obtained at the same time by using fiber wireline outside the gas injection string during gas injection. There was a field application in gas injection well of DH1-H3 and gas injection profiles derived from DTS and DAS had the extremely high consistency to radioactive tracer profiles run at about the same time and under similar injection rates and pressure. The success of the fibre-optic surveillance in DH1-H3 exhibited great potential of fiber-optic sensing in gas injection EOR projects, which could provide a new and effective tool in identifying gas channeling.


2021 ◽  
Vol 7 (20) ◽  
pp. eabe7136
Author(s):  
Robert Law ◽  
Poul Christoffersen ◽  
Bryn Hubbard ◽  
Samuel H. Doyle ◽  
Thomas R. Chudley ◽  
...  

Measurements of ice temperature provide crucial constraints on ice viscosity and the thermodynamic processes occurring within a glacier. However, such measurements are presently limited by a small number of relatively coarse-spatial-resolution borehole records, especially for ice sheets. Here, we advance our understanding of glacier thermodynamics with an exceptionally high-vertical-resolution (~0.65 m), distributed-fiber-optic temperature-sensing profile from a 1043-m borehole drilled to the base of Sermeq Kujalleq (Store Glacier), Greenland. We report substantial but isolated strain heating within interglacial-phase ice at 208 to 242 m depth together with strongly heterogeneous ice deformation in glacial-phase ice below 889 m. We also observe a high-strain interface between glacial- and interglacial-phase ice and a 73-m-thick temperate basal layer, interpreted as locally formed and important for the glacier’s fast motion. These findings demonstrate notable spatial heterogeneity, both vertically and at the catchment scale, in the conditions facilitating the fast motion of marine-terminating glaciers in Greenland.


Ground Water ◽  
2012 ◽  
Vol 51 (5) ◽  
pp. 670-678 ◽  
Author(s):  
Matthew W. Becker ◽  
Brian Bauer ◽  
Adam Hutchinson

2021 ◽  
Vol 73 (01) ◽  
pp. 12-13
Author(s):  
Manas Pathak ◽  
Tonya Cosby ◽  
Robert K. Perrons

Artificial intelligence (AI) has captivated the imagination of science-fiction movie audiences for many years and has been used in the upstream oil and gas industry for more than a decade (Mohaghegh 2005, 2011). But few industries evolve more quickly than those from Silicon Valley, and it accordingly follows that the technology has grown and changed considerably since this discussion began. The oil and gas industry, therefore, is at a point where it would be prudent to take stock of what has been achieved with AI in the sector, to provide a sober assessment of what has delivered value and what has not among the myriad implementations made so far, and to figure out how best to leverage this technology in the future in light of these learnings. When one looks at the long arc of AI in the oil and gas industry, a few important truths emerge. First among these is the fact that not all AI is the same. There is a spectrum of technological sophistication. Hollywood and the media have always been fascinated by the idea of artificial superintelligence and general intelligence systems capable of mimicking the actions and behaviors of real people. Those kinds of systems would have the ability to learn, perceive, understand, and function in human-like ways (Joshi 2019). As alluring as these types of AI are, however, they bear little resemblance to what actually has been delivered to the upstream industry. Instead, we mostly have seen much less ambitious “narrow AI” applications that very capably handle a specific task, such as quickly digesting thousands of pages of historical reports (Kimbleton and Matson 2018), detecting potential failures in progressive cavity pumps (Jacobs 2018), predicting oil and gas exports (Windarto et al. 2017), offering improvements for reservoir models (Mohaghegh 2011), or estimating oil-recovery factors (Mahmoud et al. 2019). But let’s face it: As impressive and commendable as these applications have been, they fall far short of the ambitious vision of highly autonomous systems that are capable of thinking about things outside of the narrow range of tasks explicitly handed to them. What is more, many of these narrow AI applications have tended to be modified versions of fairly generic solutions that were originally designed for other industries and that were then usefully extended to the oil and gas industry with a modest amount of tailoring. In other words, relatively little AI has been occurring in a way that had the oil and gas sector in mind from the outset. The second important truth is that human judgment still matters. What some technology vendors have referred to as “augmented intelligence” (Kimbleton and Matson 2018), whereby AI supplements human judgment rather than sup-plants it, is not merely an alternative way of approaching AI; rather, it is coming into focus that this is probably the most sensible way forward for this technology.


Author(s):  
L.S. Leontieva ◽  
◽  
E.B. Makarova ◽  

The oil and gas sector of the economy in many states remains the main source of foreign exchange and tax revenues to the budget. Moreover, its share, for example, in Russia, accounts for about 12 % of all industrial production. However, this sector, as the practice of world oil prices shows, is experiencing not only a rise, but also a decline. Consequently, the problem of forming a balanced portfolio of oil and gas assets is an object of close attention on the part of national oil and gas companies. The issues of choosing the optimal combination of oil and gas assets in the portfolio are no less urgent, especially among the tasks that all oil and gas companies face, both in Russia and abroad. An investment portfolio or a portfolio of oil and gas assets, which includes new projects for the commissioning of fields, as well as measures to enhance oil recovery, and exploration are objects of real investment. The high volatility of the oil and gas industry is influenced by various factors, including: macroeconomic, innovation risks and a number of others. These circumstances stimulate the sector to increase the resilience of its project portfolios in order to respond flexibly to changes. In an increasingly challenging and uncertain environment, oil and gas companies around the world face constant pressures as difficult strategic decisions and building long-term plans lead to a sustainable portfolio. In order to achieve their goals and maximize profitability, companies should apply certain algorithms in their practice. The article substantiates the role and importance of project portfolio management in achieving the goals of the state and companies in the oil and gas sector. The main goal of the article is to build an algorithm that is aimed both at determining the stability of the portfolio and the ability to flexibly respond to changes in the environment. The scientific novelty of the research lies in the determination of an algorithm for assessing the sustainability of a portfolio of projects of oil and gas companies. Application of this algorithm will allow oil and gas companies to take into account the influence of external factors. The research methodology is based on such methods as analysis of internal regulations and reporting of companies for project portfolio management, risk analysis, project ranking; grouping and classification method.


2015 ◽  
Vol 799-800 ◽  
pp. 196-200
Author(s):  
Abhilash M. Bharadwaj ◽  
Sonny Irawan ◽  
Saravanan Karuppanan ◽  
Mohamad Zaki bin Abdullah ◽  
Ismail bin Mohd Saaid

Casing design is one of the most important parts of the well planning in the oil and gas industry. Various factors affecting the casing material needs to be considered by the drilling engineers. Wells partaking in thermal oil recovery processes undergo extreme temperature variation and this induces high thermal stresses in the casings. Therefore, forecasting the material behavior and checking for failure mechanisms becomes highly important. This paper uses Finite Element Methods to analyze the behavior two of the frequently used materials for casing - J55 and L80 steels. Modeling the casing and application of boundary conditions are performed through Ansys Workbench. Effect of steam injection pressure and temperature on the materials is presented in this work, indicating the possibilities of failure during heating cycle. The change in diameter of the casing body due to axial restriction is also presented. This paper aims to draw special attention towards the casing design in high temperature conditions of the well.


2021 ◽  
Author(s):  
Abiola Oyatobo ◽  
Amalachukwu Muoghalu ◽  
Chinaza Ikeokwu ◽  
Wilson Ekpotu

Abstract Ineffective methods of increasing oil recovery have been one of the challenges, whose solutions are constantly sought after in the oil and gas industry as the number of under-produced reservoirs increases daily. Water injection is the most extended technology to increase oil recovery, although excessive water production can pose huge damage ranging from the loss of the well to an increase in cost and capital investment requirement of surface facilities to handle the produced water. To mitigate these challenges and encourage the utilization of local contents, locally produced polymers were used in polymer flooding as an Enhanced Oil Recovery approach to increase the viscosity of the injected fluids for better profile control and reduce cost when compared with foreign polymers as floppan. Hence this experimental research was geared towards increasing the efficiency of oil displacement in sandstone reservoirs using locally sourced polymers in Nigeria and also compared the various polymers for optimum efficiency. Starch, Ewedu, and Gum Arabic were used in flooding an already obtained core samples and comparative analysis of this shows that starch yielded the highest recovery due to higher viscosity value as compared to Ewedu with the lowest mobility ratio to Gum Arabic. Finally, the concentration of Starch or Gum Arabic should be increased for optimum recovery.


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