Combination of New Acoustic and Electromagnetic Frequency Technologies Detects Leaks Behind Multiple Casings. Case History

2021 ◽  
Author(s):  
Jose Mata ◽  
Zunerge Guevara ◽  
Luis Quintero ◽  
Carlos Vasquez ◽  
Hernando Trujillo ◽  
...  
Keyword(s):  
Water Movement ◽  
Oil And Gas Industry ◽  
Metal Loss ◽  
Success Factor ◽  
Depth Range ◽  
High Definition ◽  
Near Surface ◽  
Fluid Movement ◽  
Wide Range ◽  
Pulsed Neutron

Abstract Although leakages in well tubulars have always existed, their occurrence has become very frequent as the number of active wells in mature fields increases. The catastrophic risk of these leaks is an increase in the number of environmental accidents in the oil and gas industry. One of the fundamental causes of leaks is corrosion, which plays a negative role in the productive life of the wells. Generally, these environmental events are associated with surface or near-surface sources. Since multiple casing strings exist within this depth range, the identification of the leak location becomes extremely difficult. In view of this, the industry has put much effort in improving and new technology to be more precise and comprehensive in diagnosing these leaks. The evolution of two of such technologies will be addressed in this paper. The first one is a new electromagnetic high-definition frequency tool for pipes and multiples casing for metal loss detection. This state-of-the-art technology is a noticeable improvement over existing tools, due to an important increase in the number of sources, number of detectors and wide range of working frequencies. The combination of these changes allows for the evaluation of metal loss in up to 5 concentric casings in a single run. Furthermore, the tool is small in diameter which makes it compatible with production pipes without the need of a workover rig. This versatility obviously helps in the preworkover diagnosis before deciding to move a rig to location to eventually remedy any leak problems. The electromagnetic technology is complemented, with the latest leak detection acoustic technology. A spontaneous audio source is normally associated with downhole fluid movements. The tool has an array of 8 hydrophones with a working frequency range from 100 Hz to 100 KHz. These two different technologies based on independent fundamental principles, allows for the detection of leaks in multiple concentric pipes with great vertical and radial precision to identify the exact location of leaks as small as to 0.02 L/min. the depth of investigation of the system is up to 10 feet. Therefore, it is possible to detect fluid movement within the formation. Pulsed neutron technology was included in the study to detect water movement behind the casing to establish the flow path to the surface in addition to the leak point. A very complex acquisition program was established that was undoubtedly a key success factor in the results obtained. The electromagnetic tool determined the depth of severe casing metal loss in 7-inch casing, also the acoustic tool detected the noise of fluid movement in the 7-inch annulus, and the pulsed-neutron tool showed the beginning of water movement at the same interval the temperature log, also included in the same tool string showed a considerable change that correlated with all these logs, indicating the point of communication in this well. After establishing the uniqueness of the solution, this diagnosis helped the operator define an intervention plan for this well, and to make the appropriate corrections in the field development strategy.

Structural interpretation using refraction velocities from marine seismic surveys

Geophysics ◽  
1986 ◽  
Vol 51 (1) ◽  
pp. 12-19 ◽  
Author(s):  
James F. Mitchell ◽  
Richard J. Bolander
Keyword(s):  
Sedimentary Rock ◽  
Seismic Energy ◽  
Seismic Survey ◽  
Subsurface Structure ◽  
Seismic Reflection Data ◽  
Near Surface ◽  
Reflection Data ◽  
Wide Range ◽  
Streamer Length ◽  
Set Up

Subsurface structure can be mapped using refraction information from marine multichannel seismic data. The method uses velocities and thicknesses of shallow sedimentary rock layers computed from refraction first arrivals recorded along the streamer. A two‐step exploration scheme is described which can be set up on a personal computer and used routinely in any office. It is straightforward and requires only a basic understanding of refraction principles. Two case histories from offshore Peru exploration demonstrate the scheme. The basic scheme is: step (1) shallow sedimentary rock velocities are computed and mapped over an area. Step (2) structure is interpreted from the contoured velocity patterns. Structural highs, for instance, exhibit relatively high velocities, “retained” by buried, compacted, sedimentary rocks that are uplifted to the near‐surface. This method requires that subsurface structure be relatively shallow because the refracted waves probe to depths of one hundred to over one thousand meters, depending upon the seismic energy source, streamer length, and the subsurface velocity distribution. With this one requirement met, we used the refraction method over a wide range of sedimentary rock velocities, water depths, and seismic survey types. The method is particularly valuable because it works well in areas with poor seismic reflection data.

scholarly journals Integrating hydrogeological and second-order geo-electric indices in groundwater vulnerability mapping: A case study of alluvial environments

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Nyakno Jimmy George
Keyword(s):  
Protective Layer ◽  
Groundwater Vulnerability ◽  
Vulnerability Index ◽  
Aquifer Vulnerability ◽  
Second Order ◽  
Depth Range ◽  
Near Surface ◽  
Groundwater Vulnerability Mapping ◽  
Longitudinal Unit Conductance ◽  
S Model

AbstractAVI (Aquifer vulnerability index), GOD (groundwater occurrence, overlying lithology and depth to the aquifer), GLSI (geo-electric layer susceptibility indexing) and S (longitudinal unit conductance) models were used to assess economically exploitable groundwater resource in the coastal environment of Akwa Ibom State, southern Nigeria. The models were employed in order to delineate groundwater into its category of vulnerability to contamination sources using the first- and second-order geo-electric indices as well as hydrogeological inputs. Vertical electrical sounding technique employing Schlumberger electrode configuration was carried out in 16 locations, close to logged boreholes with known aquifer core samples. Primary or first-order geo-electric indices (resistivity, thickness and depth) measured were used to determine S. The estimated aquifer hydraulic conductivity, K, calculated from grain size diameter and water resistivity values were used to calculate hydraulic resistance (C) used to estimate AVI. With the indices assigned to geo-electric parameters on the basis of their influences, GOD and FSLI were calculated using appropriate equations. The geologic sequence in the study area consists of geo-electric layers ranging from motley topsoil, argillites (clayey to fine sands) and arenites (medium to gravelly sands). Geo-electric parametric indices of aquifer overlying layers across the survey area were utilized to weigh the vulnerability of the underlying water-bearing resource to the contaminations from surface and near-surface, using vulnerability maps created. Geo-electrically derived model maps reflecting AVI, BOD, FLSI and S were compared to assess their conformity to the degree of predictability of groundwater vulnerability. The AVI model map shows range of values of log C ( −3.46—0.07) generally less than unity and hence indicating high vulnerability. GOD model tomographic map displays a range of 0.1–0.3, indicating that the aquifer with depth range of 20.5 to 113.1 m or mean depth of 72. 3 m is lowly susceptible to surface and near-surface impurities. Again, the FLSI map displays a range of FLSI index of 1.25 to 2.75, alluding that the aquifer underlying the protective layer has a low to moderate vulnerability. The S model has values ranging from 0.013 to 0.991S. As the map indicates, a fractional portion of the aquifer at the western (Ikot Abasi) part of the study area has moderate to good protection (moderate vulnerability) while weak to poor aquifer protection (high vulnerability) has poor protection. The S model in this analysis seems to overstate the degree of susceptibility to contamination than the AVI, GOD and GLSI models. From the models, the categorization of severity of aquifer vulnerability to contaminations is relatively location-dependent and can be assessed through the model tomographic maps generated.

Basin-Wide Connections of Upper-Ocean Temperature Variability in the Equatorial Indian Ocean

2021 ◽  
pp. 1-50
Author(s):  
Ge Song ◽  
Bohua Huang ◽  
Rongcai Ren ◽  
Zeng-Zhen Hu
Keyword(s):  
Indian Ocean ◽  
Equatorial Indian Ocean ◽  
Reanalysis Data ◽  
Upper Ocean ◽  
Ocean Temperature ◽  
Ocean Reanalysis ◽  
Near Surface ◽  
Surface Warming ◽  
Transition Mechanism ◽  
Wide Range

AbstractIn this paper, the interannual variability of upper-ocean temperature in the equatorial Indian Ocean (IO) and its basin-wide connections are investigated using 58-year (1958-2015) comprehensive monthly mean ocean reanalysis data. Three leading modes of an empirical orthogonal function (EOF) analysis dominate the variability of upper-ocean temperature in the equatorial IO in a wide range of timescales. A coherent interannual band within the first two EOF modes identifies an oscillation between the zonally tilting thermocline across the equatorial IO in its peak phases and basin-wide displacement of the equatorial thermocline in its transitional phases. Consistent with the recharge oscillation paradigm, this oscillation is inherent of the equatorial IO with a quasi-periodicity around 15 months, in which the wind-induced off-equatorial Rossby waves near 5°S-10°S provide the phase-transition mechanism. This intrinsic IO oscillation provides the biennial component in the observed IOD variations. The third leading mode shows a nonlinear long-term trend of the upper-ocean temperature, including the near-surface warming along the equatorial Indian Ocean, accompanied by cooling trend in the lower thermocline originating further south. Such vertical contrary trends may lead to an enhanced stratification in the equatorial IO.

Evaporite Palynology: a case study on the Permian (Lopgingian) Zechstein Sea

2021 ◽  
pp. jgs2020-174
Author(s):  
Martha E. Gibson ◽  
David J. Bodman
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Rapid Growth ◽  
Western Europe ◽  
Thermal Maturity ◽  
Near Surface ◽  
Wide Range ◽  
Terrestrial Environments ◽  
Insight Into

Evaporites characterize the Lopingian of Europe but present obstacles for biostratigraphic analysis. Here we present a case study for processing the Lopingian Zechstein Group evaporites of central-western Europe for the recovery of palynomorph assemblages. We demonstrate that full recovery is easily achieved with two main modes of palynomorph preservation observed; palynomorphs are either exceptionally well-preserved and orange-brown in colour, or poorly-preserved, brown-black, opaque and fragmented. The latter are reminiscent of palynomorphs of high thermal maturity. However, we propose that the intact nature of preservation is a result of the rapid growth of near-surface halite crystals, with their darkening a consequence of locally-enhanced heat flux due to the relatively high thermal conductivity of salt. This case study has enabled novel insight into an otherwise undescribed environment, and demonstrates the utility and possibility of extracting palynomorphs from a variety of rock salt types. This method should be applicable to a wide range of ancient evaporite and could also be applied to other Permian evaporite systems, which are used as analogues for extra-terrestrial environments.

Study the effect of casting temperature on details from thermo-plastic materials

2020 ◽  
pp. 42-45
Author(s):  
J.A. Kerimov ◽  
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Mold Temperature ◽  
Quality Parameters ◽  
Oil Field ◽  
Casting Temperature ◽  
Gas Industry ◽  
Field Equipment ◽  
Wide Range ◽  
The Impact

The implementation of plastic details in various constructions enables to reduce the prime cost and labor intensity of machine and device manufacturing, decrease the weight of design and improve their quality and reliability at the same time. The studies were carried out with the aim of labor productivity increase and substitution of colored and black metals with plastic masses. For this purpose, the details with certain characteristics were selected for further implementation of developed technological process in oil-gas industry. The paper investigates the impact of cylinder and compression mold temperature on the quality parameters (shrinkage and hardness) of plastic details in oil-field equipment. The accessible boundaries of quality indicators of the details operated in the equipment of exploration, drilling and exploitation of oil and gas industry are studied in a wide range of mode parameters. The mathematic dependences between quality parameters (shrinkage and hardness) of the details on casting temperature are specified.

A Novel Corrosion Monitoring and Prediction System Utilizing Advanced Artificial Intelligence

2021 ◽  
Author(s):  
Klemens Katterbauer ◽  
Waleed Dokhon ◽  
Fahmi Aulia ◽  
Mohanad Fahmi
Keyword(s):  
Real Time ◽  
Oil And Gas ◽  
Salt Water ◽  
Oil And Gas Industry ◽  
Training Dataset ◽  
Metal Loss ◽  
Corrosion Monitoring ◽  
Prediction System ◽  
Well Performance ◽  
Data Driven Approach

Abstract Corrosion in pipes is a major challenge for the oil and gas industry as the metal loss of the pipe, as well as solid buildup in the pipe, may lead to an impediment of flow assurance or may lead to hindering well performance. Therefore, managing well integrity by stringent monitoring and predicting corrosion of the well is quintessential for maximizing the productive life of the wells and minimizing the risk of well control issues, which subsequently minimizing cost related to corrosion log allocation and workovers. We present a novel supervised learning method for a corrosion monitoring and prediction system in real time. The system analyzes in real time various parameters of major causes of corrosion such as salt water, hydrogen sulfide, CO2, well age, fluid rate, metal losses, and other parameters. The data are preprocessed with a filter to remove outliers and inconsistencies in the data. The filter cross-correlates the various parameters to determine the input weights for the deep learning classification techniques. The wells are classified in terms of their need for a workover, then by the framework based on the data, utilizing a two-dimensional segmentation approach for the severity as well as risk for each well. The framework was trialed on a probabilistically determined large dataset of a group of wells with an assumed metal loss. The framework was first trained on the training dataset, and then subsequently evaluated on a different test well set. The training results were robust with a strong ability to estimate metal losses and corrosion classification. Segmentation on the test wells outlined strong segmentation capabilities, while facing challenges in the segmentation when the quantified risk for a well is medium. The novel framework presents a data-driven approach to the fast and efficient characterization of wells as potential candidates for corrosion logs and workover. The framework can be easily expanded with new well data for improving classification.

Nanoemulsions: A Versatile Technology for Oil and Gas Applications

2021 ◽  
Author(s):  
Nouf AlJabri ◽  
Nan Shi
Keyword(s):  
Droplet Size ◽  
Large Scale ◽  
Oil And Gas ◽  
Volume Fraction ◽  
Oil Industry ◽  
Oil And Gas Industry ◽  
High Energy ◽  
Small Droplet ◽  
Gas Industry ◽  
Wide Range

Abstract Nanoemulsions (NEs) are kinetically stable emulsions with droplet size on the order of 100 nm. Many unique properties of NEs, such as stability and rheology, have attracted considerable attention in the oil industry. Here, we review applications and studies of NEs for major upstream operations, highlighting useful properties of NEs, synthesis to render these properties, and techniques to characterize them. We identify specific challenges associated with large-scale applications of NEs and directions for future studies. We first summarize useful and unique properties of NEs, mostly arising from the small droplet size. Then, we compare different methods to prepare NEs based on the magnitude of input energy, i.e., low-energy and high-energy methods. In addition, we review techniques to characterize properties of NEs, such as droplet size, volume fraction of the dispersed phase, and viscosity. Furthermore, we discuss specific applications of NEs in four areas of upstream operations, i.e., enhanced oil recovery, drilling/completion, flow assurance, and stimulation. Finally, we identify challenges to economically tailor NEs with desired properties for large-scale upstream applications and propose possible solutions to some of these challenges. NEs are kinetically stable due to their small droplet size (submicron to 100 nm). Within this size range, the rate of major destabilizing mechanisms, such as coalescence, flocculation, and Ostwald ripening, is considerably slowed down. In addition, small droplet size yields large surface-to-volume ratio, optical transparency, high diffusivity, and controllable rheology. Similar to applications in other fields (food industry, pharmaceuticals, cosmetics, etc.), the oil and gas industry can also benefit from these useful properties of NEs. Proposed functions of NEs include delivering chemicals, conditioning wellbore/reservoir conditions, and improve chemical compatibility. Therefore, we envision NEs as a versatile technology that can be applied in a variety of upstream operations. Upstream operations often target a wide range of physical and chemical conditions and are operated at different time scales. More importantly, these operations typically consume a large amount of materials. These facts not only suggest efforts to rationally engineer properties of NEs in upstream applications, but also manifest the importance to economically optimize such efforts for large-scale operations. We summarize studies and applications of NEs in upstream operations in the oil and gas industry. We review useful properties of NEs that benefit upstream applications as well as techniques to synthesize and characterize NEs. More importantly, we identify challenges and opportunities in engineering NEs for large-scale operations in different upstream applications. This work not only focuses on scientific aspects of synthesizing NEs with desired properties but also emphasizes engineering and economic consideration that is important in the oil industry.

The Use of Controlled Dissolution Glasses to Consolidate and Create Permeable or Impermeable Minerals in Formation

2021 ◽  
Author(s):  
Max Olsen ◽  
Ragni Hatlebakk ◽  
Chris Holcroft ◽  
Arne Stavland ◽  
Nils Harald Giske ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Oil And Gas ◽  
Stable Solution ◽  
Oil And Gas Industry ◽  
Post Treatment ◽  
Strength Increase ◽  
Glass Technology ◽  
Nuclear Waste Storage ◽  
Wide Range ◽  
Glass Compositions

Abstract Scope Controlled dissolution glasses form a permanent consolidating mineral matrix inside formations with either permeable or impermeable properties. The unique solution has a low injection viscosity and can be easily injected into a wide range of formations. The application method is simple and does not require multiple fluids or pre- and post-flushing. This paper focuses on the benefits of controlled dissolution glasses and potential applications in the oil and gas industry. Methods, Procedures, Process Controlled dissolution glasses have been researched extensively by Glass Technology Services (GTS) since 1999 for the biomedical industry, nuclear waste storage industry, and defense and aerospace industries. GTS together with operators have been performing research and development for the oil industry over the last 10 years. The research investigated different glass compositions to determine their injectability and change in formation properties post-treatment. Sandstone, chalk, and shale formations were used in the testing. Flow testing using a Hoek cell and a core flood apparatus was used to determine the post-treatment permeability. For post-treatment strength measurement, Brazilian tensile strength tests and modified cone penetration tests were used to determine tensile strength and shear strength respectively. The testing evaluated different mixing fluids, such as water and different brines, compatibility, corrosion testing, and concentrations. Results, Observations, Conclusions The testing identified different glass compositions and concentrations that are suitable for different applications and formations. Certain glass compositions increase tensile strength significantly while also maintaining the permeability in the formation. Other glass compositions have similar tensile strength increase, but result in an impermeable seal. The liquid glass solutions react with the formation to form a mineral precipitation inside the formation. The reaction with the formation occurs quickly at downhole conditions, within hours of placement. The glass can be mixed with water and variety of brines to form a stable solution across a range of densities. The testing and results to date have laid the foundation for use in a variety of consolidation and P&A applications in oil and gas wells. Testing is ongoing for a chalk and sandstone consolidation solution and for a sealing solution. Novel/Additive Information These novel glass solutions can solve many of the production and instability challenges that plague weak formations. The glasses can be injected into very low permeability formation to either seal or consolidate.

Model and Experimental Estimates of Vertical Mixing Intensity in the Sea Upper Homogeneous Layer

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
A. M. Chukharev ◽  
M. I. Pavlov ◽  
◽  
Keyword(s):  
Experimental Data ◽  
Turbulence Intensity ◽  
Multiscale Model ◽  
Turbulent Exchange ◽  
Stokes Drift ◽  
Homogeneous Layer ◽  
Depth Range ◽  
Near Surface ◽  
Langmuir Circulations ◽  
Turbulence Generation

Purpose. The study is aimed at qualitative and quantitative analysis (based on the updated previously proposed multiscale model) of the experimental data on turbulence intensity and their comparison with theoretical and semi-empirical relationships for the purpose of describing the contributions of various turbulence sources. Methods and Results. A comparative analysis of experimental data and model calculations of turbulence characteristics near the sea surface was performed. The methods of theoretical assessing generation of turbulence in the near-surface sea layer by various physical processes are considered. The results of calculations by the well-known models of turbulent exchange were compared with the experimental data collected by the scientists of the Turbulence Department of MHI, RAS, using the specialized equipment. The analysis results made it possible to determine the possibility of applying the considered models for calculating turbulence intensity under different hydrometeorological conditions. At light winds, none of the models yielded the results which matched the measurement data. At moderate winds, the simulation results showed quite satisfactory agreement with the experiment data; and for strong winds, the multiscale model results were the best. This model was modified to assess the contributions of two other mechanisms of turbulence generation: the Stokes drift and the Langmuir circulations. Conclusions. Objective assessment of the turbulent exchange intensity requires taking into account of three main mechanisms of turbulence generation, namely flow velocity shear, wave motions and wave breaking. Depending on the hydrometeorological situation, each of these mechanisms can dominate in a certain depth range. The calculations performed using the updated model showed that the Stokes drift added 2–17 % to the total dissipation in the upper 30-meter layer, whereas the contribution of the Langmuir circulations calculated through dependence of the vertical velocity of kinetic energy transfer upon the Langmuir number, can reach 15 % for small Langmuir numbers.

scholarly journals Radiocesium in the Taiwan Strait and the Kuroshio east of Taiwan from 2018 to 2019

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wei-Jen Huang ◽  
Ming-Ta Lee ◽  
Kuei-Chen Huang ◽  
Kai-Jung Kao ◽  
Ming-An Lee ◽  
...  
Keyword(s):  
Water Column ◽  
Surface Waters ◽  
Half Life ◽  
North Pacific Ocean ◽  
Taiwan Strait ◽  
Depth Range ◽  
Near Surface ◽  
Activity Concentrations ◽  
The Taiwan Strait ◽  
The Kuroshio

AbstractThe release of anthropogenic radiocesium to the North Pacific Ocean (NPO) has occurred in the past 60 years. Factors controlling 137Cs (half-life, 30.2 year) and 134Cs (half-life, 2.06 year) activity concentrations in the Kuroshio east of Taiwan and the Taiwan Strait (latitude 20° N–27° N, longitude 116° E–123° E) remain unclear. This study collected seawater samples throughout this region and analyzed 134Cs and 137Cs activity concentrations between 2018 and 2019. A principal component analysis (PCA) was performed to analyze the controlling factors of radiocesium. Results of all 134Cs activity concentrations were below the detection limit (0.5 Bq m−3). Analyses of water column 137Cs profiles revealed a primary concentration peak (2.1–2.2 Bq m−3) at a depth range of 200–400 m (potential density σθ: 25.3 to 26.1 kg m−3). The PCA result suggests that this primary peak was related to density layers in the water column. A secondary 137Cs peak (1.90 Bq m−3) was observed in the near-surface waters (σθ = 18.8 to 21.4 kg m−3) and was possibly related to upwelling and river-to-sea mixing on the shelf. In the Taiwan Strait, 137Cs activity concentrations in the near-surface waters were higher in the summer than in the winter. We suggest that upwelling facilitates the vertical transport of 137Cs at the shelf break of the western NPO.

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