Optical Cable Research Articles

Особенности цифровизации арктических регионов России

The article discusses the features of digitalization in the Arctic regions of Russia. The authors pose broad questions: why is it important to develop the Arctic now; what economic interests are behind this; what difficulties are associated with this process; and how can we assess the current level of digital transformation in the Russian part of the Arctic? Based on an analysis of data from the Federal State Statistics Service and forecast indicators for the socio-economic development of regions, the authors assess the current level of digitalization of the Arctic regions of the Russian Federation as uneven. The issue of digitalization requires increased attention in the Chukotka Autonomous Okrug and the Republic of Karelia. The authors concluded that the digitalization of the Arctic repeats the features of the digitalization of the country: the digitalization of business and industry lags the public sector and households. The main problems are associated with the large financial costs of laying fiber optic cables in remote, hard-to-reach areas with few residents. The authors believe that the most relevant tool for solving existing problems could be joint investments of public and private raw materials companies in laying a fiber-optic cable along the bottom of the Arctic Ocean for the digitalization of the Northern Sea Route (hereinafter referred to as the NSR), as well as across the territory of coastal Arctic subjects. The authors assess the digitalization of the NSR as vital for the development of this logistics route and as the main and most economically beneficial for the development of trade relations with China.

Near real-time nautical depth mapping via horizontal optical fibers and distributed acoustic sensing

Safe navigation in ports and waterways subjected to siltation requires nautical depth monitoring. For this purpose, surveying vessels equipped with a zero-offset echo sounder and intrusive point measurements are frequently used. Because these measurements depend on the availability of a surveying vessel and require access to quay walls, such as at the container terminals in seaports, the temporal resolution is limited. Especially at these locations, a high temporal resolution monitoring system could allow for a higher occupancy rate. We propose to use Distributed Acoustic Sensing to monitor the nautical depth using fiber-optical cables. We install five horizontal fibers at different heights between two points and continuously record along the complete installation. Analysing the continuous recordings, we show that horizontal fibers can be used to monitor the water-mud interface depth with a vertical resolution around six mm. Multiple passive sources, like vessel movements and water currents, are used to estimate the water-mud interface.

Data encryption with chaotic light in the long wavelength infrared atmospheric window

In environments where traditional fiber optic cables are impractical, free-space optical communications offer a promising solution for transmitting large amounts of data, especially in the mid-infrared wavelength range. Despite the advantages of minimal atmospheric interference and stable signals, the vulnerability of wireless optical communications to eavesdropping poses a significant challenge. This study addresses this challenge by demonstrating a method for privately transmitting optical data using photonic chaos from distributed feedback quantum cascade lasers operating at 9.3 µm. Signal processing techniques are applied to enhance the quality of the transmission over distances exceeding 30 m, accompanied by a comprehensive analysis of the photonic chaos complexity to ensure data confidentiality. These findings mark a significant advancement in developing private communications systems within the thermal atmospheric window, with a substantially reduced risk of interception by adversaries. The research not only contributes to secure communications but also has potential implications for enhancing security of data transmission in challenging environments, impacting various industries and applications.

Protecting against micropollutants in water storage tanks using in-situ TiO2 coated quartz optical fibers

Photocatalyst-coated optical fibers (P-OFs) using UV-A LEDs offer a highly promising solution for the degradation of micropollutants within municipal, reuse, industrial or home distribution systems, by integrating P-OFs into water storage tanks. P-OFs have photocatalysts attached to bundles of optical fibers, enabling their direct deployment within tanks. This eliminates the necessity for photocatalyst slurries, which would require additional membrane or separation systems. However, a current limitation of P-OFs is light management, specifically light oversaturation of the coated photocatalysts and short light transmission distances along fibers. This study overcomes this limitation and reveals strategies to improve the light dissipation uniformity along P-OFs, and demonstrates the performance of P-OFs on degrading a model micropollutant, carbamazepine (CBZ). Key tunable variables of fibers and light emission conditions, including photocatalyst coating patchiness (p), minimum light incident angles (θm), radiant flux launched to fibers (Φi), and fiber diameters (D), were modeled to establish their relationships with the light dissipation uniformity in TiO2-coated quartz optical fibers (TiO2-QOFs). We then validated modeling insights by conducting experiments to examine how these variables influence the generation of evanescent waves which are localized energy on fiber surfaces, leading to either photocatalyst activation or the recapture of unused light back into fibers. We observed substantial enhancements in evanescent waves generation by decreasing p and increasing θm, resulting in uniform light dissipation which reduces light oversaturation and improves light transmission distances. Moreover, these optimizations led to a remarkable three-fold improvement in CBZ degradation rates and a 65% reduction in energy consumption. Such improvement substantially reduces the capital and operational cost and enhances practicality of energy-efficient photocatalysis without additional chemical oxidants for micropollutant degradation in water storage tanks.

A distributed-temperature-sensing-based soil temperature profiler

Abstract. Storage change in heat in the soil is one of the main components of the energy balance and is essential in studying the land–atmosphere heat exchange. However, its measurement proves to be difficult due to (vertical) soil heterogeneity and sensors easily disturbing the soil. Improvements in the precision and resolution of distributed temperature sensing (DTS) equipment has resulted in its widespread use in geoscientific studies. Multiple studies have shown the added value of spatially distributed measurements of soil temperature and soil heat flux. However, due to the spatial resolution of DTS measurements (∼30 cm), soil temperature measurements with DTS have generally been restricted to (horizontal) spatially distributed measurements. This paper presents a device which allows high-resolution measurements of (vertical) soil temperature profiles by making use of a 3D-printed screw-like structure. A 50 cm tall probe is created from segments manufactured with fused-filament 3D printing and has a helical groove to guide and protect a fiber-optic (FO) cable. This configuration increases the effective DTS measurement resolution and will inhibit preferential flow along the probe. The probe was tested in the field, where the results were in agreement with the reference sensors. The high vertical resolution of the DTS-measured soil temperature allowed determination of the thermal diffusivity of the soil at a resolution of 2.5 cm, many times better than what is feasible using discrete probes. A future improvement in the design could be the use of integrated reference temperature probes, which would remove the need for DTS calibration baths. This could, in turn, support making the probes “plug and play” into the shelf instruments without the need to splice cables or experience in DTS setup design. The design can also support the integration of an electrical conductor into the probe and allow heat tracer experiments to derive both the heat capacity and the thermal conductivity over depth at high resolution.

Voiceprint and position information detection of non-cooperative ship with Φ-OTDR and suspended sensitized optical cable

Target detection is significant in many fields, including oceanic security, marine ecology, etc. In this paper, phase sensitive optical time domain reflectometry (Φ-OTDR) is introduced for the non-cooperative ship detection, with large-scale diversity technology and suspended sensitized optical cable. In outfield experiments, the ship’s voiceprint information is obtained in high fidelity, the ship’s power spectrum is analyzed, and the over-top detection is achieved. Moreover, an array orientation method based on adaptive phase difference correction (APDC) is proposed to track the ship, suppressing the delay jitter influence of acoustic transmission underwater. This is the first time that voiceprint information of the non-cooperative ship is high-fidelity acquired and deeply analyzed with Φ-OTDR and suspended sensitized optical cable, which is conducive to the detection and identification of marine targets, and proves the potential of Φ-OTDR in hydroacoustic detection applications.

Adaptive Vibration Monitoring of Railway Track Structures Using the UWFBG by the Identification of Train-Load Patterns

Due to the capability of multiplexing thousands of sensors on a single optical cable, ultra-weak fiber Bragg grating (UWFBG) vibration sensing technology has been utilized in monitoring the vibration response of large-scale infrastructures, particularly urban railway tracks, and the volume of the collected monitoring data can be huge with the great number of sensors. Even though the train-induced vibration responses of urban railway tracks constitute the most informative and crucial component, they comprised less than 7% of the total operational period. This is mainly attributed to the temporal sparsity of commuting trains. Consequently, the majority of the stored data consisted of low-informative environmental noise and interference excitation data, leading to an inefficient structural health monitoring (SHM) system. To address this issue, this paper introduced an adaptive monitoring strategy for railway track structures, which is capable of identifying train-load patterns by leveraging deep learning techniques. Inspired by image semantic segmentation, a U-net model with one-dimensional convolution layers (U-net-1D) was developed for the pointwise classification of vibration monitoring data. The proposed model was trained and validated using a dataset obtained from an actual urban railway track in China. Results indicated that the proposed method outperforms the traditional dual-threshold method, achieving an Intersection over Union (IoU) of 94.27% on the segmentation task of the test dataset.

Seismic Magnitude Estimation Using Low-Frequency Strain Amplitudes Recorded by DAS Arrays at Far-Field Distances

ABSTRACT Downhole distributed acoustic sensing (DAS) data are now routinely acquired on fiber-optic cables deployed in wells for seismic imaging and microseismic monitoring. We develop a semiempirical workflow for estimating scalar seismic moment and moment magnitude of earthquakes using strain data recorded by downhole DAS arrays. At far-field distances, the time integral of axial strain is proportional to the displacement scaled by apparent slowness. Therefore, seismic moment can be directly estimated from the amplitude of the low-frequency plateau of the strain spectra divided by frequency, similar to the methodology commonly employed for far-field displacement spectra. The effect of polarization on strain amplitudes for different types of body waves is accounted for. Benefitting from the large spatial coverage provided by DAS arrays, moment estimates from multiple channels are averaged and an average radiation coefficient is assumed over the focal sphere. We validate the methods using data of microseismic events simultaneously recorded by a surface geophone array and by DAS on fiber deployed in two horizontal wells during a hydraulic fracturing experiment. For 106 microseismic events in the magnitude range ∼ −0.65 to ∼ +0.55, we find the DAS-derived magnitudes to be consistent with the magnitudes derived from the geophone array using traditional methods, with ∼95% of the magnitude estimates differing by less than ∼0.26 units. The workflow can be potentially extended to DAS arrays in vertical wells and to S waves recorded on dark fiber DAS arrays at the surface. This methodology does not require any calibration beyond knowledge of local seismic properties, and the use of the lowest possible frequencies reduces the influence of subsurface heterogeneities and the finite spatiotemporal extent of earthquake ruptures. The capacity to estimate robust seismic magnitudes from downhole DAS arrays allows improved evaluation and management of fracture growth and more effective mitigation of induced seismicity.

Analisis Gangguan Transmisi Fiber Cut dan Pengembangan Solusi untuk Meningkatkan Availability Sistem Komunikasi Fiber Optik Section Banua Hanyar – Bati Bati

Technology continues to develop very quickly, especially long-distance communication and transmission technology. This is due to the increasing human need for the internet, as seen by its availability. The main objective of this research is to analyze the impact and solution to Fiber Cut transmission on availability in the Banua Hanyar - Bati Bati Section. This research uses a correlative descriptive quantitative method to obtain a solution, namely replacing ordinary fiber optic cables and many existing cable with a new anti-rodent fiber optic cable 3 km long located 0.8 km to 3.8 km from Banua Hanyar. This solution is said to be very influential because it succeeded in increasing the availability of the Banua Hanyar - Bati Bati Section system to 100%.

A hybrid approach combining OFC and FSO for multichannel connectivity

Abstract This paper presents a novel approach of establishing a multichannel optical communication link, combining optical fiber cable (OFC) and free space optics (FSO) technology. By leveraging multiple lengths of optical fiber and FSO links, along with optical amplifiers to counteract attenuation, our proposed hybrid system incorporates four channels operating within the 1550 nm window. This model is specifically designed to address communication challenges in scenarios such as unplanned urban layouts, multistory buildings, or rugged terrains where traditional optical fiber deployment is impractical. By integrating FSO for the fronthaul and optical fiber for the backhaul, our system enhances transmission capacity, thereby supporting the requirements of next-generation networks and alleviating bottlenecks and connectivity issues at the last or first mile. This innovative approach holds promise for internet service providers, enterprises, and industrial networks operating in demanding environments. Furthermore, it can serve as a vital tool for restoring emergency communication links in the aftermath of disasters such as earthquakes or floods, where traditional wired optical infrastructure may be compromised.

Evaluating Internet Network Quality: A Comprehensive Analysis by the PNUP Directorate of Building

This study raises the problem of the condition of the building network of the Directorate of PNUP which has an irregular cabling structure so that if a network installation is carried out by connecting to the nearest switch without regard to cable paths, the cables are not on the path according to the irregular distribution of IP networks and bandwidth. The purpose of this study is to enhance the quality of the internet network in the PNUP Directorate building, compare the network performance before and after revitalizing fiber optic cables, and determine the internet bandwidth requirements in the PNUP Directorate building. The method employed is assessing internet network performance using Quality of Service parameter, by evaluating when the implementation that has been carried out is deemed sufficient, the evaluation is carried out based on the test results of the Quality of Service parameter. The user speed test is performed on public IP, followed by data recording and capture using tilnet tools. The values for delay, throughput, packet loss, and jitter are then processed and calculated. The outcome of this research demonstrates that network revitalization has successfully increased bandwidth usage, particularly in data transmission (Tx). Additional capacity and increased network performance after the revitalization allow for greater and more efficient use of bandwidth in transmitting data.

Optical fiber bundle differential compressive imaging.

We present a differential compressive imaging method for an optical fiber bundle (OFB), which provides a solution for an ultrathin bend-resistant endoscope with high resolution. This method uses an OFB and a diffuser to generate speckle illumination patterns. Differential operation is additionally applied to the speckle patterns to produce sensing matrices, by which the correlation between the matrices is greatly reduced from 0.875 to 0.0275, which ensures the high quality of image reconstruction. Pixilation artifacts from the fiber core arrangement are also effectively eliminated with this configuration. We demonstrate high-resolution reconstruction of images of 132 × 132 pixels with a compression rate of 12% using 77 fiber cores, the total diameter of which is only about 91 µm. An experimental verification proves that this method is tolerant to a limited degree of fiber bending, which provides a potential approach for robust high-resolution fiber endoscopy.

3D DAS VSP for Coal Seam Exploration: A Case Study from Queensland, Australia.

Seismic methods are extensively used in coal mining for expanding resource discoveries and definition as well as for mine monitoring. However, the use of borehole seismic methods is relatively uncommon due to the high cost of borehole seismic acquisition using conventional downhole tools. The introduction of distributed acoustic sensing (DAS), which uses optical fibres to record seismic data, has dramatically increased the cost-effectiveness of borehole seismic methods. Fibre-optic cables are inexpensive and, once deployed in a borehole, can be abandoned or used later for further monitoring of the subsurface. The case study presented here concerns the use of DAS to record a 3D VSP (vertical seismic profiling) for coal seam exploration in Queensland, Australia. This study trialled effective strategies for deploying cables into boreholes and demonstrated how this technology could be incorporated into the standard coal exploration process. The final processing results produced a high-resolution 3D seismic cube where the coal seams below the basalt cover are clearly identifiable around the boreholes. Permanent installation of the fibre-optic cables into a set of boreholes provides immediate benefits of 3D seismic imaging and can create additional value in utilising these sensors for further discrete or continuous subsurface measurements, including stability monitoring of underground workings and detection of methane accumulations.

A Survey of the Mechanisms Impairing Optical fiber communications performance

The growth of information technology and Internet networks, combined with nearly daily use and many subscribers, has caused the volume of data stored in communication systems to balloon to enormous proportions. Optical fiber cable is the medium for data transfer because it has a bandwidth far more significant than other transmission methods and can span significantly greater distances. The transmission of information from one location to another can be accomplished via a technique known as fiber-optic communication. This involves passing pulses of light over an optical fiber. Optical fiber performance is affected by many effects, including attenuation, dispersion, scattering, and bending. It is feasible to enhance the performance of optical fibers for communications by utilizing carbon nanotubes and multiple coding technologies. This can be accomplished via integrated optical circuits or by making the cable more advanced and developing it further. Photosynthesis is accomplished by utilizing carbon tubes and the optical property inside them.

Laser-irradiating infrared attenuated total reflection spectroscopy of articular cartilage: Potential and challenges for diagnosing osteoarthritis

ObjectiveA prototype infrared attenuated total reflection (IR-ATR) laser spectroscopic system designed for in vivo classification of human cartilage tissue according to its histological health status during arthroscopic surgery is presented. Prior to real-world in vivo applications, this so-called osteoarthritis (OA) scanner has been tested at in vitro conditions revealing the challenges associated with complex sample matrices and the accordingly obtained sparse spectral datasets. MethodsIn vitro studies on human knee cartilage samples at different contact pressures (i.e., 0.2–0.5 ​MPa) allowed recording cartilage degeneration characteristic IR signatures comparable to in vivo conditions with high temporal resolution. Afterwards, the cartilage samples were assessed based on the clinically acknowledged osteoarthritis cartilage histopathology assessment (OARSI) system and correlated with the obtained sparse IR data. ResultsAmide and carbohydrate signal behavior was observed to be almost identical between the obtained sparse IR data and previously measured FTIR data used for sparse partial least squares discriminant analysis (SPLSDA) to identify the spectral regions relevant to cartilage condition. Contact pressures between 0.3 and 0.4 ​MPa seem to provide the best sparse IR spectra for cylindrical (d ​= ​3 ​mm) probe tips. ConclusionLaser-irradiating IR-ATR spectroscopy is a promising analytical technique for future arthroscopic applications to differentiate healthy and osteoarthritic cartilage tissue. However, this study also revealed that the flexible connection between the laser-based analyzer and the arthroscopic ATR-probe via IR-transparent fiberoptic cables may affect the robustness of the obtained IR data and requires further improvements.

METHOD OF EVALUATION THE EFFICIENCY OF FIBER-OPTIC CABLES MODELS WITH MULTI-MODULAR DESIGN BASED ON MASS AND DIMENSIONAL INDICATORS

Context. Today, the leading cable production plants in many countries of the world manufacture single- and multi-module designs of fiber-optic cables (FOC) with different protective covers and the number of fibers. This creates a wide range of possible FOC models for different consumer (buyer) requirements. However, the lack of openness of prices for FOC for the consumer, in particular for the project organization, and the desire of the manufacturer to save on production creates a need for the development and research of a method for evaluating the effectiveness of FOC of a multi-module design. In the work, it is proposed to do this by analyzing a number of optical cable models according to parameters-criteria – the compactness coefficient and the economic efficiency coefficient of the FOC by diameter. Objective. To develop a method of evaluation the efficiency of fiber-optic cables models with multi-modular design based on mass-dimensional indicators, which will allow to quickly choose an appropriate model of the FOC with the given initial data. Method. A method of evaluating the efficiency of the FOC modular design has been developed and proposed. It is based on the comparison of cable models and the selection of the most appropriate of them at given initial data. The paper proposed and introduced parameters-criteria for this – the compactness coefficient υ and the efficiency coefficient according to the diameter of the cable E0 – which show the connection of the design characteristics of the FOC to a certain parameter of its structure. At the same time, the most effective model (design) of the FOC compared to the basic models in terms of technical conditions, both from the point of view of the manufacturer and the customer, consists in lower material costs for its production while simultaneously ensuring the specified requirements for the cable (first of all, number of fibers and mechanical strength). This will allow, at the stage of cable design, to make an appropriate choice of its model with given initial parameters and to develop such a design of the FOC, which will allow to minimize the dimensions (and therefore the material capacity and cost) of the model without losing its quantitative and qualitative characteristics. Results. The paper presents the results of the development and research of the method of evaluating the efficiency of the FOC with multi-module structure based on mass and dimensional indicators. For example, using the developed method, it is shown that it is possible to choose a FOC model with a diameter smaller by 10.9% and save 15.5% of the cable cost for each kilometer of the fiber optic communication line while ensuring the initial requirements for the cable. Conclusions. The scientific novelty of the work results is that, method of evaluation the efficiency of a modular FOC design has been first developed, which allows at the cable design stage to compare the model with the cable design according to the technical conditions (TC) and the appropriate choice of this model with the given initial parameters. The practical significance lies in the possibility of using this method to make an accelerated selection of the cable model at the stage of its design, while simultaneously providing the necessary capacity of the FOC with optical fibers and minimizing the cost of its materials and dimensions.

ANALISIS GANGGUAN DAN IDENTIFIKASI KABEL FIBER OPTIC MENGGUNAKAN OTDR DI OTB CIREBON-BREBES R4

Fiber optic cables that experience interference and breaks are a common problem in modern communications infrastructure. Interference and breaks in optical cables can disrupt data transmission between locations and cause a decrease in signal quality. The use of an Optical Time Domain Reflectometer (OTDR) has become a common method for detecting faults in optical cables by displaying the attenuation of the cable under test. Although optical fiber has a large capacity and high speed for transmitting information, relatively small attenuation still has a significant impact on transmission quality. The importance of maintaining and handling this interference is because attenuation can cause power loss in fiber optic transmission, hamper data transmission, and affect the quality of internet services

Thermal stress simulation analysis of aerospace optical fibers and connectors and related extensions to high-speed railway area

Aerospace optical cables and fiber-optic connectors have numerous advantages (e.g., low loss, wide transmission frequency band, large capacity, light weight, and excellent resistance to electromagnetic interference). They can achieve optical communication interconnections and high-speed bidirectional data transmission between optical terminals and photodetectors in space, ensuring the stability and reliability of data transmission during spacecraft operations in orbit. They have become essential components in high-speed networking and optically interconnected communications for spacecrafts. Thermal stress simulation analysis is important for evaluating the temperature stress concentration phenomenon resulting from temperature fluctuations, temperature gradients, and other factors in aerospace optical cables and connectors under the combined effects of extreme temperatures and vacuum environments. Considering this, advanced optical communication technology has been widely used in high-speed railway communication networks to transmit safe, stable and reliable signals, as high-speed railway optical communication in special areas with extreme climates, such as cold and high-temperature regions, requires high-reliability optical cables and connectors. Therefore, based on the finite element method, comprehensive comparisons were made between the thermal distributions of aerospace optical cables and J599III fiber optic connectors under different conditions, providing a theoretical basis for evaluating the performance of aerospace optical cables and connectors in space environments and meanwhile building a technical foundation for potential optical communication applications in the field of high-speed railways.

Experimental study on progressive interfacial mechanical behaviors using fiber optic sensing cable in frozen soil

Frost heave and thaw settlement in cold regions pose a significant threat to engineering construction. Optical frequency domain reflectometry (OFDR) based on Rayleigh scattering can be applied to monitor ground deformation in frozen soil areas, where the interface behavior of soil-embedded fiber optic sensors governs the monitoring accuracy. In this paper, a series of pullout tests were conducted on fiber optic (FO) cables embedded in the frozen soil to investigate the cable‒soil interface behavior. An experimental study was performed on interaction effects, particularly focused on the water content of unfrozen soil, freezing duration, and differential distribution of water content in frozen soil. The high-resolution axial strains of FO cables were obtained using a sensing interrogator, and were used to calculate the interface shear stress. The interfacial mechanical response was analytically modeled using the ideal elasto‒plastic and softening constitutive models. Three freezing periods, correlating with the phase change process between ice and water, were analyzed. The results shows that the freezing effect can amplify the peak shear stress at the cable-soil interface by eight times. A criterion for the interface coupling states was proposed by normalizing the pullout force‒displacement information. Additionally, the applicability of existing theoretical models was discussed by comparing the results of theoretical back‒calculations with experimental measurements. This study provides new insights into the progressive interfacial failure behavior between strain sensing cable and frozen soil, which can be used to assist the interpretation of FO monitoring results of frozen soil deformation.

Monitoring, Modeling Techniques Help Optimize Eagle Ford Completions

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 212367, “Sealed Wellbore Pressure Monitoring and Calibrated Fracture Modeling: The Next Step in Unconventional Completions Optimization,” by Karen Olson, SPE, Joshua Merritt, and Rair Barraez, SPE, Well Data Labs, et al. The paper has not been peer reviewed. _ Sealed wellbore pressure monitoring (SWPM) has been used across North and South America, with more than 16,000 stages monitored. A recent development is the added capability of a fracture model that can automatically history-match the volume to first response (VFR) determined from SWPM. The complete paper’s focus is a case study of the Department of Energy Eagle Ford refracturing project, where a range of completion designs were trialed while monitoring offset SWPM and fiber-optic strain. Introduction of the Hydraulic Fracture Test Site 1 (HFTS1), Phase 3 Background. The HFTS1 Phase 3 was conducted at the Zgabay unit in northwest DeWitt County, Texas. This unit was initially developed with horizontal multistage completions and has been producing since 2013. The 10 original wells in the unit, and the four new drilled wells, are landed in the approximately 100-ft-thick Lower Eagle Ford Shale. Of the four new drills, Well 14H is a dedicated observation well instrumented with various diagnostics, including a permanent fiber-optic cable. Well 12H, another new drill, was monitored using a wireline-deployable fiber. Both of these wells featured downhole gauges, while Wells 11H and 13H featured surface gauges. The focus of the refracturing strain diagnostics— SWPM and fiber—was to characterize new fracture growth and interaction with pre-existing fractures during the liner refracturing of parent Wells 5H and 3H. Completion Designs. Multiple stage and cluster architectures were tested on the Zgabay Wells 3H and 5H. Four single-cluster stages were performed per well. Both a high (2,000-psi target) and low (500-psi target) perforation friction design was tested on seven-, 12-, and 22-cluster stages. Well 3H maintained a slightly tighter cluster spacing (10–15 ft) compared with the 12–20 ft spacing of Well 5H. The main method of measuring the effect of different designs is strain monitoring using SWPM and fiber optics. Technology Background SWPM. SWPM uses an uncompleted wellbore to monitor fracture intersections from offset-well stimulations. The monitor well collecting the SWPM data cannot be connected to a formation through perforations or other types of access points. The wellbore should be filled with low-compressibility fluid, with pressure added to the monitor well. Fractures intersecting the sealed wellbore cause local deformation, which results in a small volume reduction in the closed system and generates a discernable and distinct pressure response. The total slurry injected into the stage of the active well when the first fracture arrival is identified using SWPM is the VFR. VFRs are used as a proxy for cluster efficiency and to calculate fracture-growth rates. The field execution of SWPM does not require any tools to enter the wellbore. Multiple sealed wellbores can be used as monitor wells for a single treatment well.