Slant Hole Research Articles

Research on the Application of Slant Hole Grouting Process in the Undermining Hollow Area of Urban Main Road

China has a huge number of underground goaf, when the new city main road crosses the goaf, a large number of non-migratable buildings may be left on the ground due to economic problems, resulting in the goaf does not have the condition of vertical drilling and grouting, so the slant hole grouting technology is of great significance in research. In this paper, we take a city main road under construction in Changchun City as an example to study the application of slant hole drilling grouting in the hollow area, and hope that it can provide reference examples for similar projects.

Blazed photon sieve for the correction of presbyopia.

What we believe to be a new type of transparent photon sieve is presented with application for presbyopia correction. Inspired by blazed gratings, we propose to design an intracorneal implant with slanted holes. The slopes introduce a new degree of freedom, breaking the symmetry of energy distribution along the optical axis and allowing to balance the energy between near and far vision. This new implant design is presented together with the simulation, manufacturing and validation methods. The first experimental results obtained with an implant manufactured in a biocompatible material are presented confirming the potential of the approach.

Multilateral Jetting Technology Results in Increased Production in Offshore Field

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 21959, “Multilateral Jetting Technology Results in a 150% Uplift in Production During a Second Offshore Application in Abu Dhabi Offshore Field,” by Salman Farhan Nofal, SPE, Fazeel Ahmad, SPE, and Ahmad Shmakhy, SPE, ADNOC, et al. The paper has not been peer reviewed. Copyright 2022 International Petroleum Technology Conference. Reproduced by permission. A well offshore Abu Dhabi was deemed a success despite deployment challenges during the lower completion phase. Opportunities to address these challenges existed for a succeeding well, and in the search for improvement to the productivity index (PI), multilateral acid-jetting technology was adopted as a more-effective approach than typical drainage methods. Following successful adoption of this technology, the well has been producing for 1 year at the time of writing with positive results. Introduction The subject reservoir consists of a carbonate multilayer formation with differing porosities and permeabilities. The conventional method to inject or produce from these layers is by drilling slanted or horizontal holes followed by acidizing using conventional 15 or 28% hydrochloric acid (HCl). These holes sometimes do not meet the target because of low productivity (high drawdown) caused by tight reservoirs with less surface contact even after acidizing because the acid tends to propagate more in the highly permeable streaks than in the low-permeability ones. The new approach aims at addressing this problem by increasing the surface contact in the low-permeability streaks and connecting different thin separated layers to improve productivity using expanding metal needles. Challenges This reservoir consists of multiple thin, low-permeability layers separated by dense layers. Completion of wells in all sublayers with slanted holes did not lead to efficient production, and high drawdown led to low bottomhole flowing pressure. Completion of wells in one or two sublayers using horizontal stepdown was considered, but some wells were still not able to produce against the sea line, leading to the conclusion that the reservoirs suffered from a low ratio of vertical to horizontal permeability (kV/kH).

Drilling the new 5G-5 branch hole at Vostok Station for collecting a replicate core of old meteoric ice

AbstractRecent studies have shown that stratigraphically disturbed meteoric ice bedded at Vostok Station between 3318 and 3539 m dates back to 1.2 Ma BP and possibly beyond. As part of the VOICE (Vostok Oldest Ice Challenge) initiative, a new deviation from parent hole 5G-1 was made at depths of 3270–3291 m in the 2018/19 austral season with the aim of obtaining a replicate core of the old ice. Sidetracking was initiated using the standard KEMS-132 electromechanical drill routinely employed for deep ice coring at Vostok, without significant changes to its initial design. Here we describe the method and operating procedures for replicate coring at a targeted depth in an existing slant hole, involving the use of a cable-suspended electromechanical drill. The design of the milling cutter head used for sidetracking is presented. The performance characteristics and the experience of drilling branch-hole 5G-5 at Vostok are described and discussed.

The evaluation of slant hole collimator in myocardial perfusion SPECT: a simulation study

Introduction: We have investigated cardiac SPECT with slant hole collimator in which the holes are slanted towards the target organ, to provide greater sensitivity over the parallel hole collimator. In addition, parallel hole collimator was used to obtain a comparison in FWHM, sensitivity, Compton and photoelectric area values in the simulations. Materials and Methods: A NaI: Tl crystal with a parallel and slant hole collimators were employed in the simulations. The collimator holes were slanted at a specific angle range of 0-30 degree. The NCAT phantom and a filtered-back projection algorithm was used for data generation and image reconstruction. The projection data acquired from the LAO position to provide lower attenuation to the heart. We also evaluated conventional MPS utilizing LEHR parallel hole collimator for the sake of comparison. Results: The evaluation of the reconstructed data showed that the FWHM for PH-SPECT ranged from 9.9 to 10.4 mm, while that for SH-SPECT ranged from 17 to 19 mm. The sensitivity values showed that conventional SPECT with 18.9 Cps/MBq, while that SH-SPECT provided higher sensitivity (18.93 to 25.21 Cps/MBq) compared with PH-SPECT. Furthermore, the Compton and photoelectric area in energy spectrum were 5.62 and 8.62%, 5.7 and 21.67% respectively for PH and SH SPECT. Conclusion: SH-SPECT is able to acquire higher sensitivity gain over the PH-SPECT.

Effects of Trichoderma harzianum YC459 and soil types on seed germination and seedling growth in rock slope restoration

We carried out experiments with various concentrations of Trichoderma harzianum YC459 in different soil types (forest soil, mixed soil, merchantable soil, and leaf mold soil) to evaluate its effect on seed germination and seedling establishment of four species (Festuca arundinacea Schreb., Dianthus barbatus var. asiaticus Nakai, Lespedeza cyrtobotrya Miq., and Parthenocissus tricuspidata Planch) for rock slope restoration. We also investigated the use of drilled slanted holes on the rock slopes for seedling establishment. The results showed that T. harzianum concentration had significant effects on seed germination, seedling growth, and seedling survival for all the species with different soil types. Seed germination and survival rates peaked at 5% T. harzianum concentration with leaf mold soil and decreased as T. harzianum concentration increased from 5% to 10%. Seedling survival rates of all four species were generally lowest at 0% T. harzianum concentration in all soil types. The height of F. arundinacea and L. cyrtobotrya peaked at 5% T. harzianum concentration whereas that of D. barbatus and P. tricuspidata peaked at 10% T. harzianum concentration. We concluded that 5% T. harzianum concentration with leaf mold soil is appropriate for seed germination and seedling survival rates of most species, thus enhancing seedling establishment. Practical application of the findings of this study will contribute in the vegetation restoration of steep rocks in mountain environments

Revegetation of Rock Slopes with Different Substrates in an Abandoned Quarry in Jinju, Korea

The purpose of this research was to investigate the use of drilled slanted holes filled with different substrates in the revegetation of rock slopes. Slanted holes were drilled on rock slopes using pneumatic drillers in an abandoned limestone quarry area. These holes were filled with twelve different substrates, treated with Trichoderma harzianum. One climbing plant of Ivy (Hedera rhombea), a native woody plant (Lespedeza cyrtobotrya), three native herbaceous plants (Dianthus barbatus, Siberian chrysanthemum and Aster koraiensis) and one exotic grass plant (Festuca arundinacea) were planted in each of the soils. Six months after planting, only Ivy, Festuca arundinacea, Lespedeza cyrtobotrya and Dianthus barbatus were still observed growing on the soils, while the other plant species had already died in all the 12 soil treatments. Leaf mold soil + 50% Trichoderma harzianum provide the best conditions for revegetation of Festuca arundinacea, as this plant had its highest mean height, high survival rate, with impressive growth rate on this soil. Lespedeza cyrtobotrya also had its most favorable growth on Leaf mold soil + 50% T. harzianum. Mixed soil + 100% T. harzianum provide the best conditions for revegetation of Ivy. Leaf mold soil + 100% T. harzianum provide the best condition for revegetation of Dianthus barbatus as it had its highest mean height, highest growth rate and high survival rate on this soil. Siberian chrysanthemum and Aster koraiensis had the worse results as all of the plants died within a short period of time after planting. Ivy had the highest mean height, followed by Festuca arundinacea. The planted Ivy and Festuca arundinacea now form the vegetation of the research site which together with the substrate is now providing habitat to some wildlife like some species of centipedes, earthworms, insects and wild plants. Less than one year after planting, F. arundinacea already produced flowers and seeds which would further increase the plant population after dispersal and germination. Drilling slanted holes on rock slopes is therefore a feasible method to be used for revegetation and restoration of degraded quarries.The revegetation of steep rock slopes of quarries is a very challenging activity. However, the method of drilling slanted holes on rock slopes is a feasible method to be used for restoration of degraded quarries. These holes could serve in soil deposition and water retention that will further enhance plant growth.Methods of improving seed germination as well as enhancing growth of plants are also imperative in revegetation success of such degraded landscapes. Different percentage mixtures of T. harzianum in different soils could enhance plant growth depending on the target plant species. Different substrates could thus be used in such revegetation process depending on the target plant species.Revegetation would provide habitat and improve landscape beauty and stability, thus it is important for successful restoration of rock slopes

Gamma emission tomosynthesis based on an automated slant hole collimation system

The imaging capabilities of radioisotope molecular imaging systems are limited by their ring geometry and by the object-to-detector distance, which impairs spatial resolution, efficiency and image quality. These detection capabilities could be enhanced by performing acquisitions with dedicated gamma cameras placed in close proximity to the object that has to be examined. The main aim of this work is to develop a compact camera suitable for detecting small and low-contrast lesions, with a higher detection efficiency than conventional SPECT, through a gamma emission tomosynthesis method. In this contribution a prototype of a new automated slant hole collimator, coupled to a small Field of View (FoV) gamma camera, is presented. The proposed device is able to acquire planar projection images at different angles without rotating around the patient body; these projection images are then three-dimensional reconstructed. Therefore, in order to perform the volumetric reconstruction of the studied object, the traditional Back Projection (BP) reconstruction is compared with the Shift And Add (SAA) method. In order to verify the effectiveness of the technique and to test the image reconstruction algorithms, a Monte Carlo simulation, based on the GEANT4 code, was implemented. The method was also validated by a set of experimental measurements. The discussed device is designed to work in patient proximity for detecting lesions placed at a distances ranged from 0 to 8 cm, thus allowing few millimeters planar resolutions and sagittal resolution of about 2 cm. The new collimation method implies high-resolution capabilities demonstrated by reconstructing the projection images through the BP and the SAA methods. The latter is simpler than BP and produces comparable spatial resolutions with respect to the traditional tomographic method, while preserving the image counts.

Molecular Imaging of the Breast Using a Variable-Angle Slant-Hole Collimator

Purpose: The purpose of this work is to develop an improved method for 3D molecular imaging of the breast using limited angle SPECT. Methods: The proposed method uses a variable-angle slant-hole (VASH) collimator. Rather than rotate the camera around the breast, the VASH collimator allows limited angle, tomographic acquisition while the detector remains stationary and flush against the compression paddle. This design minimizes object-to-detector distance for high spatial resolution. Theoretical analysis is presented of VASH spatial resolution and sensitivity, including depth-of-interaction (DOI) effects and magnification. The theory is compared with Monte Carlo simulation results for a point source and breast phantom including a compression paddle. An iterative reconstruction method for the slant hole data is used. Results: The theoretical model of the VASH system showed good agreement with Monte Carlo simulations based on spatial resolution, including DOI effects, and sensitivity. For 140 keV photons and a NaI(Tl) scintillator, the DOI effect resulted in roughly a 2 mm loss in spatial resolution only in depth dimension; in the other two dimensions the spatial resolution was not affected by DOI. In reconstructed breast phantom images, VASH out-performed a parallel hole SPECT approach in terms of contrast-to-noise ratio. Conclusions: The proposed method for breast imaging using limited angle SPECT and a VASH collimator demonstrated the potential for superior spatial resolution/sensitivity. In addition to high spatial resolution/sensitivity, the system design has advantages of simple detector motion, ability to image close to the chest wall and conducive to on-board biopsy and multi-modal imaging with mammography.

微細粒組織を有するSUS304極薄板への微細穴の斜め打抜きにおける材料変形挙動

微細粒組織を有するSUS304極薄板への微細穴の斜め打抜きにおける材料変形挙動

The Sinusoidal Buckling Mechanical Analysis for the Coiled Tubing Based on Energy Method

Columns are prone to sinusoidal buckling and repeated instability on the effect of drilling pressure and fluid pressure during drilling operation. The resulted large area of random contact to borehole wall would affect the drilling efficiency. It made the backreaming and loading hard and the drilling pressure low. Using energy method, taking flexural deformation energy and external potential energy of strings, hole section (slant hole, bending hole, level hole) and annular clearance etc. into consideration, derived the counting function of force that sinusoidal buckling occurred on coiled tubing when it contact with the wellbore, establishing the mechanical analysis method of calculating for sinusoidal buckling of slim lined construction roof bolt and string borehole. It proves an effective method for the applying of coiled tubing drilling pressure and the optimization of process parameters.

Estimation of Fan Beam and Parallel Beam Parameters in a Wire Mesh Design

Special collimators used in imaging systems play an important part in obtaining qualified images to improve diagnosis in medicine. The primary aim of this study was to compare resolution between fan beam and parallel beam collimators using Monte Carlo simulation in the shape of cubic holes. Also, parameters such as geometric efficiency, geometric resolution, scatter, penetration, and full width at half maximum were studied to compare their special characteristics. The simulation results demonstrated that the geometry efficiency of a fan beam collimator increased as the angle of the slant hole increased, and the geometric resolution decreased as the angle of the slant hole increased, at a distinct distance from a monoenergetic source of γ-rays. In contrast, at a distinct angle, geometric resolution increased as the distance between the source and the collimator surface increased. For both collimators, scatter and penetration decreased as the distance increased. These results were in agreement with ADAC company data. Finally, fan beam collimators were found to have better resolution than parallel beam collimators with a cubic hole shape in a wire mesh design. Estimation of the fan beam by parallel beam parameters as cubic holes can be suitable in collimator design to improve resolution and efficiency.

Selecting a Completion Strategy for Sand Control and Optimal Production Rate - Unayzah Sandstone Reservoir

This article, written by Senior Technology Editor Dennis Denney, contains highlights of paper SPE 131078, ’Selection of Completion Strategy for Sand Control and Optimal Production Rate - Field Examples From Saudi Arabia's Unayzah Sandstone Reservoir,’ by Zillur Rahim, SPE, Bandar Al-Malki, SPE, and Adnan Al-Kanaan, Saudi Aramco, prepared for the 2010 SPE Asia Pacific Oil & Gas Conference and Exhibition, Brisbane, Australia, 18-20 October. The paper has not been peer reviewed. For field development, it is important to identify reservoir structure, heterogeneity, rock properties, and fluid characteristics to select an optimal development strategy for enhancing production and increasing recovery in a cost-effective manner. Therefore, a detailed reservoir description and characterization is required by use of geo-physical, geological, and engineering data. This condensate-rich, high-flow-capacity, and highly sanding deep gas reservoir was developed gradually and optimized to select the most appropriate drilling-and-completion technique. Introduction Saudi Aramco’s SA-1 field produces from the Permian Unayzah formation. The first well drilled penetrated the Unayzah-A zone in 1997 and showed excellent reservoir quality. Cores were collected from the well and, subsequently, from other wells confirming unconsolidated reservoir rock with low Young’s modulus and compressive-strength values. To avoid sanding during production, early wells in this field were completed as vertical wellbores with frac-pack stimulation using premium screens, even though difficulties were encountered during frac-pack installation. With technology advances in drilling and completion, the development method shifted to drilling horizontal and highly slanted holes. This method eliminated deploying the frac-pack system, increased reservoir contact substantially, and improved well performance. To protect well integrity and eliminate sand production, expandable sand screens (ESSs) were used for completing the wells. Higher sustained gas rates were achieved with a reduced non-Darcy skin, sanding was eliminated, and risks related to deployment of the completion equipment (ESS) were reduced.

微細傾斜穴3次元プレス工法の開発と燃料噴射弁への適用

微細傾斜穴3次元プレス工法の開発と燃料噴射弁への適用

The application of on-chip optofluidic microscopy for imaging Giardia lamblia trophozoites and cysts

The optofluidic microscope (OFM) is a lensless, low-cost and highly compact on-chip device that can enable high-resolution microscopy imaging. The OFM performs imaging by flowing/scanning the target objects across a slanted hole array; by measuring the time-varying light transmission changes through the holes, we can then render images of the target objects at a resolution that is comparable to the holes' size. This paper reports the adaptation of the OFM for imaging Giardia lamblia trophozoites and cysts, a disease-causing parasite species that is commonly found in poor-quality water sources. We also describe our study of the impact of pressure-based flow and DC electrokinetic-based flow in controlling the flow motion of Giardia cysts--rotation-free translation of the parasite is important for good OFM image acquisition. Finally, we report the successful microscopy imaging of both Giardia trophozoites and cysts with an OFM that has a focal plane resolution of 0.8 microns.

Validation of an iterative reconstruction for a mobile tomographic gamma camera system—The Cardiotom

The Cardiotom is a mobile gamma camera that uses ectomography, an alternative method of acquisition to SPECT. It is designed for early diagnosis of myocardial and cerebral infarctions in the emergency room. Ectomography is a limited view angle method, using a rotating slant hole collimator and a stationary camera head, to acquire projection images. The aim of this work was to validate a fully 3D ML–EM iterative reconstruction algorithm for the Cardiotom. Validation measurements were performed with 99mTc point sources. Resolution in the reconstructed volume was determined in X, Y, and Z directions from the point spread functions. The results were compared with the values for the formerly used filtered back projection (FBP). The new reconstruction algorithm provides greatly improved depth resolution with respect to the FBP method previously implemented on the Cardiotom. Furthermore, for clinical examinations, images can be available for interpretation within 15 min of the injection, therefore, valuable information can be obtained without delaying treatment of the patient.

Slanted hole array beam profiler (SHArP)—a high-resolution portable beam profiler based on a linear aperture array

We demonstrate a novel high-resolution portable beam profiler based on a slanted linear array of small apertures, termed a slanted hole array beam profiler (SHArP). The apertures are directly fabricated on a metal-coated CMOS imaging sensor. With a single linear scan, the aperture array can establish a virtual grid of sampling points for beam profiling. With our prototype, we demonstrate beam profiling of Gaussian beams over an area of 66.5 microm x 66.5 microm with a resolution of 0.8 microm (compare with the CMOS pixel size of 10 microm). The resolution can be improved into the range of submicrometers by fabricating smaller apertures. The good correspondence between the measured and calculated beam profiles proves the fidelity of our new beam profiling scheme.

An analysis of an alternative scintimammography system

A novel system for scintimammography has been developed, which has high spatial resolution, good sensitivity, better energy resolution, and lower cost than conventional systems. In addition, the system incorporates the potential to provide additional information and functionality beyond imaging, including x,y and z lesion location, integration with a stereotatic biopsy system and images both breasts at the same time. Methods: The system uses sheet NaI (Tl) crystals, PM Tubes, and slant hole collimators allowing complete separation of the breast from the chest wall while remaining in contact with the breast at all depths. The physical characteristics are presented, with images and compared with other systems. Results: The limit of lesion detectability in terms lesion size, depth and contrast has been investigated and compared with a current conventional system. Using accepted patient dose data, the anticipated radiopharmaceutical activity related to the lesion size is used for imaging tests and provides a measure of expected of lesion detectability. Conclusion: Large area, sheet NaI (Tl) detector systems with slant hole collimators are capable of imaging features of below 5mm size at both surface and at clinical depths with the amount of activity expected in lesions of this size with patient administered doses in the clinically acceptable range.

Trends of Research on New Designs of Diamond Drilling Bits Made by Volgaburmash

This paper discusses the major trends of research: minimizing unbalance of forces acting on the cutting elements of the bit to reduce vibrations; creation of bits with a set controllability to optimize hole deviation (for slant hole directional drilling systems); and creation of bicentric bits with shortened bodies, increased dimension of drilling sludge channels, and better outfitting of the expanding part.

Bedside tomographic scintigraphy: a diagnostic tool in intensive care and the emergency room

Scintigraphic tomography (SPECT) with a gamma camera is an established tool for the diagnosis of disturbances in perfusion of the myocardium. The technique has been shown to be useful in the management of patients with acute myocardial infarction. However, SPECT is not widely used for seriously ill patients due to the need to transport the patient to the gamma camera system. In order to make tomography available by the bedside, a form of limited view angle tomography, Ectomography, has been implemented on a mobile gamma camera system. Projection data are acquired by rotating a slant hole collimator in front of the stationary detector and therefore, the head gantry is simple and easily transported. The mobile system is completely self-contained providing acquisition, reconstruction and bedside display. System sensitivity can be increased by using a segmented collimator, making it possible to present reconstructed sections for diagnosis less than 10 min after the start of acquisition. At present, reconstruction is performed with 2D filtered back projection. A comparative study of patients with suspected coronary artery disease has shown that Ectomography and SPECT yield similar diagnostic information. In an experimental study, in which a coronary artery was occluded, it has been possible to use Ectomography to define myocardial area at risk and final infarct size. Myocardial imaging has been performed in the intensive care unit and a pilot study has demonstrated that brain scans can also be performed. Bedside tomographic scintigraphy has been shown to be feasible and studies can be performed without moving the patient. The method should provide, therefore, an alternative to SPECT in intensive care and the emergency room.