Dynamic motion monitoring of a 3.6 km long steel rod in a borehole during cold-water injection with distributed fiber-optic sensing

Abstract. Fiber-optic distributed acoustic sensing (DAS) data finds many applications in wellbore monitoring such as e.g. flow monitoring, formation evaluation, and well integrity studies. For horizontal or highly deviated wells, wellbore fiber-optic installations can be conducted by mounting the sensing cable to a rigid structure (casing/tubing) which allows for a controlled landing of the cable. We analyze a cold-water injection phase in a geothermal well with a 3.6 km long fiber-optic installation mounted to a ¾” sucker-rod by using both DAS and distributed temperature sensing (DTS) data. During cold-water injection, we observe distinct vibrational events (shock waves) which originate in the reservoir interval and migrate up- and downwards. We use temperature differences from the DTS data to determine the theoretical thermal contraction and integrated DAS data to estimate the actual deformation of the rod construction. The results suggest that the rod experiences thermal stresses along the installation length – partly in the compressional and partly in the extensional regime. We find strong evidence that the observed vibrational events originate from the release of the thermal stresses when the friction of the rod against the borehole wall is overcome. Within this study, we show the influence of temperature changes on the acquisition of distributed acoustic/strain sensing data along a fiber-optic cable suspended along a rigid but freely hanging rod. We show that observed vibrational events do not necessarily originate from induced seismicity in the reservoir, but instead, can originate from stick-slip behavior of the rod construction that holds the measurement equipment.

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Monitoring cold water injections for reservoir characterization using a permanent fiber optic installation in a geothermal production well in the Southern German Molasse Basin

Geothermal Energy ◽

10.1186/s40517-021-00204-0 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Felix Schölderle ◽

Martin Lipus ◽

Daniela Pfrang ◽

Thomas Reinsch ◽

Sven Haberer ◽

...

Keyword(s):

Reservoir Characterization ◽

Fiber Optic ◽

Cold Water ◽

Dynamical Behavior ◽

Water Injection ◽

Vertical Displacement ◽

Thermal Contraction ◽

Distributed Temperature Sensing ◽

Production Well ◽

Geothermal Fields

AbstractFiber optic sensing has gained importance for wellbore monitoring and reservoir characterization in geothermal fields as it allows continuous, spatially highly resolved measurements. Distributed acoustic sensing (DAS) and distributed temperature sensing (DTS) technologies, among others, enable monitoring of flow regimes and heat transport inside the wellbore to describe the dynamical behavior of the reservoir. The technically challenging installation of a permanent fiber optic monitoring system in a geothermal production well over the entire wellbore length was conducted for the first time at the geothermal site Schäftlarnstraße in Munich, Germany. One cable with two DAS fibers, two DTS fibers, and one fiber for a downhole fiber optic pressure/temperature gauge were clamped to ¾-in. sucker rods and installed to 3.7 km measured depth to collect data from the wellbore after drilling, during testing, and during operations. We present DTS profiles during 3 months of well shut-in and show the results of two cold water injection tests conducted to localize inflow zones in the reservoir and to test the performance of the fiber optic setup. A vertical displacement in temperature peaks of approximately 1.5 m was observed during the injection tests, presumably resulting from thermal contraction of the sucker rod–cable setup. This was verified by analyzing the strain information from the DAS records over 1 h of warm-back after cold water injection with the calculated theoretical thermal contraction of DTS of the same period. We further verified the flowmeter measurements with a gradient velocity analysis of DTS profiles during injection. Intake to the major inflow zone was estimated to 93.5% for the first injection test, respective 94.0% for the second, intake of flowmeter was calculated to 92.0% for the same zone. Those values are confirmed by analyzing DTS profiles during the warm-back period after the well was shut.

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Fiber Optic Strain Sensing at the Sand Face Enables Real-Time Flow Monitoring and Compaction Mitigation in Openhole Applications

10.2118/147439-ms ◽

2011 ◽

Cited By ~ 3

Author(s):

Denise M. Earles ◽

Carl W. Stoesz ◽

Nilufer Darius Surveyor ◽

Alpha Liang ◽

Hans DeJongh

Keyword(s):

Real Time ◽

Fiber Optic ◽

Strain Sensing ◽

Flow Monitoring ◽

Time Flow

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Value of DTS in Multi-Stacked Reservoirs to Better Understand Injectivity and Water Flood Effectiveness – A Field Example from the UAE

10.2118/206103-ms ◽

2021 ◽

Author(s):

Jorge Gomes ◽

Jane Mason ◽

Graham Edmonstone

Keyword(s):

Lower Cretaceous ◽

Fiber Optic ◽

Water Movement ◽

Water Injection ◽

Reservoir Management ◽

Oil Production ◽

Temperature Sensing ◽

Dense Layer ◽

Distributed Temperature Sensing ◽

Injection Water

This paper highlights the application of downhole fiber optic (FO) distributed temperature sensing (DTS) measurements for well and reservoir management applications: 1) Wellbore water injectivity profiling. 2) Mapping of injection water movement in an underlying reservoir. The U.A.E. field in question is an elongated anticline containing several stacked carbonate oil bearing reservoirs (Figure 1). Reservoir A, where two DTS monitored, peripheral horizontal water injectors (Y-1 and Y-2) were drilled, is less developed and tighter than the immediately underlying, more prolific Reservoir B with 40 years of oil production and water injection history. Reservoirs A and B are of Lower Cretaceous age, limestone fabrics made up of several 4th order cycles, subdivided by several thin intra dense, 2-5 ft thick stylolitic intervals within the reservoir zones. Between Reservoir A and Reservoir B there is a dense limestone interval (30-50 ft), referred as dense layer in the Figure 1 well sections.

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Water Injection Profiling Using Fiber Optic Sensing by Applying the Novel Pressure Rate Temperature Transient PTRA Analysis

10.2118/204713-ms ◽

2021 ◽

Author(s):

Mohammed Al-Hashemi ◽

Daria Spivakovskaya ◽

Evert Moes ◽

Peter in ‘t Panhuis ◽

Gijs Hemink ◽

...

Keyword(s):

Fiber Optic ◽

Water Injection ◽

Physical Factors ◽

Distributed Temperature Sensing ◽

Data Set ◽

Temperature Transient ◽

History Of ◽

Transient Data ◽

Fiber Optic Sensing ◽

The Impact

Abstract Fiber Optic Systems, such as Distributed Temperature Sensing (DTS), have been used for wellbore surveillance for more than two decades. One of the traditional applications of DTS is injectivity profiling, both for hydraulically fractured and non-fractured wells. There is a long history of determining injectivity profiles using temperature profiles, usually by analyzing warm-back data with largely pure heat conduction models or by employing a so-called "hot-slug" approach that requires tracking of a temperature transient that arises at the onset of injection. In many of these attempts there is no analysis performed for the key influencing physical factors that could create significant ambiguity in the interpretation results. Among such factors we will consider in detail is the possible impact of cross-flow during the early warm-back stage, but also the temperature transient signal that is related to the location of the fiber-optic sensing cable behind the casing when the fast transient data are used for interpretation such as the "hot slug" during re-injection. In this paper it will be shown that despite all such potential complications, the high frequency and quality of the transient data that can be obtained from a continuous DTS measurement allow for a highly reliable and robust evaluation of the injectivity profile. The well-known challenge of the ambiguity of the interpretation, produced by the interpretation methods that are conventionally used, is overcome using the innovative "Pressure Rate Temperature Transient Analysis" method that takes maximum use of the complete DTS transient data set and all other available data at the level of the model-based interpretation. This method is based on conversion of field measurements into injectivity profiles taking into account the uncertainty in different parts of the data set, which includes the specifics of the DTS deployment, the uncertainty in surface flow rates, and possible data gaps in the history of the well. Several case studies will be discussed where this approach was applied to water injection wells. For the analysis, the re-injection and warmback DTS transient temperature measurements were taken from across the sandface. Furthermore, for comparison, injection profiles were also recorded by conventional PLTs in parallel. This case study will focus mostly on the advanced interpretation opportunities and the challenges related to crossflow through the wellbore during the warm-back phase, related to reservoir pressure dynamics, and finally related to the impact of the method of DTS deployment. In addition to describing the interpretation methodology, this paper will also show the final comparison of the fiber-optic evaluation with the interpretation obtained from the reference PLTs.

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Ecological niche modelling of cold-water corals in the Southern Ocean (N Antarctic), present distribution and future projections due to temperature changes

Marine Ecology Progress Series ◽

10.3354/meps13085 ◽

2019 ◽

Vol 628 ◽

pp. 73-93

Author(s):

S Chaabani ◽

PJ López-González ◽

P Casado-Amezua ◽

H Pehlke ◽

L Weber ◽

...

Keyword(s):

Southern Ocean ◽

Ecological Niche ◽

Cold Water ◽

Ecological Niche Modelling ◽

Niche Modelling ◽

Future Projections ◽

Temperature Changes ◽

Present Distribution

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Microanchored borehole fiber optics allows strain profiling of the shallow subsurface

Scientific Reports ◽

10.1038/s41598-021-88526-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Cheng-Cheng Zhang ◽

Bin Shi ◽

Song Zhang ◽

Kai Gu ◽

Su-Ping Liu ◽

...

Keyword(s):

Fiber Optics ◽

Field Experiments ◽

Fiber Optic ◽

Strain Sensing ◽

Near Surface ◽

Shallow Subsurface ◽

Buried Cables ◽

Capacity Theory ◽

Confining Pressures ◽

Strain Determination

AbstractVertical deformation profiles of subterranean geological formations are conventionally measured by borehole extensometry. Distributed strain sensing (DSS) paired with fiber-optic cables installed in the ground opens up possibilities for acquiring high-resolution static and quasistatic strain profiles of deforming strata, but it is currently limited by reduced data quality due to complicated patterns of interaction between the buried cables and their surroundings, especially in upper soil layers under low confining pressures. Extending recent DSS studies, we present an improved approach using microanchored fiber-optic cables—designed to optimize ground-to-cable coupling at the near surface—for strain determination along entire lengths of vertical boreholes. We proposed a novel criterion for soil–cable coupling evaluation based on the geotechnical bearing capacity theory. We applied this enhanced methodology to monitor groundwater-related vertical motions in both laboratory and field experiments. Corroborating extensometer recordings, acquired simultaneously, validated fiber optically determined displacements, suggesting microanchored DSS as an improved means for detecting and monitoring shallow subsurface strain profiles.

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Thermodynamics of a fast-moving Greenlandic outlet glacier revealed by fiber-optic distributed temperature sensing

Science Advances ◽

10.1126/sciadv.abe7136 ◽

2021 ◽

Vol 7 (20) ◽

pp. eabe7136

Author(s):

Robert Law ◽

Poul Christoffersen ◽

Bryn Hubbard ◽

Samuel H. Doyle ◽

Thomas R. Chudley ◽

...

Keyword(s):

Fiber Optic ◽

Basal Layer ◽

Temperature Sensing ◽

Distributed Temperature Sensing ◽

Catchment Scale ◽

Outlet Glacier ◽

Coarse Spatial Resolution ◽

High Vertical Resolution ◽

Fast Motion ◽

Strain Heating

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.

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Effective Method for Diagnosing Continuous Welded Track Condition Based on Experimental Research

Energies ◽

10.3390/en14102889 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2889

Author(s):

Jacek Kukulski ◽

Piotr Gołębiowski ◽

Jacek Makowski ◽

Ilona Jacyna-Gołda ◽

Jolanta Żak

Keyword(s):

Experimental Research ◽

Thermal Stresses ◽

Longitudinal Force ◽

Climatic Conditions ◽

Traffic Load ◽

Empirical Formulas ◽

Correct Operation ◽

Temperature Changes ◽

Track Condition ◽

Very High

The correct operation of the continuous welded track requires diagnosing its condition and preparation of track metrics requiring measurements of displacements of rail under operation. This is required as there are additional thermal stresses in the rails with values depending on the temperature changes of the rails. Therefore, the climatic conditions are important. This paper presents the original effective analytical method for diagnosing the condition of continuous welded track based on experimental research. The method allows for an appropriate repair or maintenance recommendation. In the experimental research, the authors considered track diagnostic conditions for two conditions: track under load and track without load. This paper presents empirical formulas for calculating rail temperature and longitudinal force based on ambient temperature, developed from long-term measurements. The formulas were developed for a track located on a straight section—both for a rail loaded and unloaded with a passing train under the following conditions: 60E1 rail, not on an engineering structure, conventional surface, wooden sleepers and very high train traffic load. The obtained results in the value of the correlation coefficient R2 ≥ 0.995 attest to very high accuracy of the calculations performed with the method proposed by the authors.

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