Ground Drilling Research Articles

Safe distances for transforaminal posterior lumbar interbody fusion under one-hole split endoscopy: three-dimensional reconstruction measurement of 1-degree degenerative lumbar spondylolisthesis at the L4/5 segment

BackgroundOne-hole split endoscopy (OSE) is a novel endoscopic technique that offers some advantages in spinal surgery. However, without a clear understanding of the safe zone for OSE, surgeons risk injuring nerve roots during the procedure. This study aimed to measure the safe distances among critical bone markers, the intervertebral space and nerve roots between 1-degree degenerative lumbar spondylolisthesis (DLS) and non-DLS at the L4/5 segment in patients via three-dimensional reconstruction and to compare the differences in relevant safety distances between the two groups. These findings provide a theoretical reference for the safe application of the OSE technique in transforaminal posterior lumbar interbody fusion (TPLIF).MethodsThe CT data of 56 patients were obtained, including 30 patients with 1-degree DLS at the L4/5 segment (DLS group) and 26 patients with non-DLS (non-DLS group). The bone markers were determined in a three-dimensional model. The relevant distances were as follows: (1) Vertical distance (VD): inferior articular process tip (IAPT) to the upper margin of the intervertebral space (VD1); superior articular process tip and the highest point of the mammillary process (HPMP) to the lower margin of the intervertebral space (VD2, VD3). (2) Horizontal distance (HD): the lateral boundary to the medial boundary at the upper margin of the intervertebral space (HD1) and at the lower margin of the intervertebral space (HD2); the medial margin of the articular surface in the coronal position of the superior articular process to the medial boundary at the lower margin of the intervertebral space (HD3); and the HPMP to the lateral boundary at the upper margin of the intervertebral space (HD4) and at the lower margin of the intervertebral space (HD5).ResultsIn the DLS group and non-DLS group, the VD1 were (10.97 ± 2.15) mm and (11.32 ± 1.70) mm, the VD2 were (11.06 ± 1.75) mm and (10.96 ± 0.91) mm, the VD3 were (4.76 ± 1.54) mm and (5.01 ± 1.02) mm, the HD1 were (10.54 ± 1.49) mm and (10.97 ± 1.06) mm, the HD2 were (17.43 ± 2.01) mm and (17.32 ± 1.70) mm, and the HD3 were (2.21 ± 0.99) mm and (2.11 ± 1.33) mm. These measurement distances were not significantly different between the two groups. While HD4 (4.17 ± 1.41) mm in the DLS group was significantly greater than HD4 (3.29 ± 1.78) mm in the non-DLS group, HD5 (1.89 ± 0.93) mm in the DLS group was significantly lower than HD5 (2.63 ± 1.45) mm in the non-DLS group (P < 0.05). There was no significant difference between VD1 and VD2 in the DLS group.ConclusionBone markers represent a novel positioning method for the treatment of 1-degree L4/5 segmental DLS under OSE, which will aid in avoiding nerve root injury and provide a reference for the safety of TPLIF. If HPMP is used as an auxiliary bone marker for decompression of the L4 exiting nerve root, HD4 was greater and HD5 was lower in the DLS group than in the non-DLS group during outwards fenestration and decompression. To improve safety, individualized imaging evaluation can be performed before the operation to select the appropriate grinding drill.

Research on the drilling state intelligent sensing and adaptive optimization control of the fast drilling robot

Abstract The fast drilling robot is the most intelligent mining drilling equipment at present. The drilling state intelligent sensing and adaptive control technology are developed to solve the problem of the intelligent control of the drilling process. According to the engineering practice, with drilling efficiency as the control target, the characteristics of the working process of the fast drilling robot and the influence of boundary conditions such as sticking probability, slag-discharge smoothness, and anchorage stability on the drilling process are analyzed. Corresponding mathematical formulas are derived, and the mathematical model of the drilling state intelligent sensing and adaptive control is constructed. The adaptive control technology based on the differential evolution algorithm is developed to realize the automatic optimization of control parameters. The ground drilling tests prove that intelligent sensing and adaptive control technology can adjust the control parameters quickly when the drilling rock changes so that the drilling robot can maintain an efficient and stable drilling state.

Preconditioning High-Strength Boulders for TBM Tunnelling by Ground Drilling and Blasting

A spherical weathering body, also called a boulder, is an element of complex geological strata and presents a significant challenge to tunnelling by a tunnel-boring machine (TBM). In this study, ground-based drilling and blasting were used to precondition boulders. To determine the specific charge needed for preconditioning blasting, model blasts were conducted, and the relationships among the specific charge, fragment size, and overburden depth in the model blasts were investigated. The determined specific charge from the model blasts was then modified by considering the overburden depth and used to precondition the boulders for practical TBM tunnelling. The results indicate the following: (1) model blasts were effective in determining the correct specific charge and predicting boulder fragment sizes resulting from blasting; (2) the boulders met in practical TBM tunnelling were successfully preconditioned by using the determined specific charge; (3) the determined specific charge was 3.26 kg/m3, corresponding to an average fragment size 4.5 cm with an overburden of zero and increased with increasing overburden; (4) fragment sizes were dependent on both the specific charge and overburden depth. Our conclusions can be used to accurately determine the specific charge instead of empirical formulas.

응력 집중 저감을 위한 머드 모터 커넥팅 로드 설계 개선에 관한 연구

Ground drilling technology for drilling has an environment where the major parts are prone to damage due to high stress, torque, and harsh operating conditions that can occur in the rotary power transfer structure. Research for preventing this damage is very important, as it can be coupled with the nature of drilling operations that take a long time in operation, which can lead to enormous cost and time consumption. Previous work investigated the cause of damage by analyzing the working environment and breakage of drilling holes for connecting rods, and a power transfer component of directional mud motors used in ground drilling systems. The material properties by heat treatment conditions for applied materials were analyzed. Based on prior work, we evaluated whether the stress concentration part shown in the analysis results matched the actual damage occurring point by conducting a structural analysis of the connecting rod, a damaged part, using the finite element analysis. We also analyzed how to reduce the stress concentration phenomenon that occurs during the mud motor operation by conducting part shape and design changes between the connecting rod and key parts.

Analysis of Chang’e-5 lunar core drilling process

Chang’e-5 explorer successfully acquired lunar regolith core samples from depths of greater than 1 m of lunar surface. This study analyzed the lunar core drilling process based on the telemetry data, image information, and returned samples to optimize the sampling device design and enhance the understanding of the lunar regolith. In particular, a prediction method for the projected drilling path and local terrain fitting of drilling dip angle was proposed based on the flight events recorded during the core drilling process and the image information acquired before, during, and after sampling. The results revealed that the drilling dip angle of Chang’e-5 was approximately 2.3°, and the deviation of the drilling length and depth was less than 2 mm. For continuous drilling, a fusion method based on telemetry data and image information was applied to determine the demarcation point of drilling with and without the lunar soil. The position of the demarcation point implied that the drilling point remained at approximately 6 mm loose soil, thereby lagging the action of the force response. Additionally, a characteristic parameter comparison method was proposed for the lunar and ground drilling to analyze the status of the lunar soil. Furthermore, the analysis results revealed that the majority of the Chang’e-5 drilling samples were derived from 0–73.8 cm below the lunar surface and few samples were extracted below 73.8 cm, as the drilling encountered several rocky regions. Moreover, the drilling point exhibited two prominent stratification variations at ∼28.7 cm and ∼70 cm below the lunar surface. Ultimately, the preliminary relationship between sample dissected position in soft tube and drilling displacement was analyzed. The segmented estimation results can support research on subsurface lunar soil.

Ulnar Groove Plasty Guided by a 3D Printing Technique for Moderate to Severe Cubital Tunnel Syndrome Caused by Elbow Osteoarthritis.

BackgroundThe purpose of this study was to explore the feasibility of ulnar groove plasty guided by a three-dimensional (3D) printing technique for treatment of moderate to severe cubital tunnel syndrome (CuTS) caused by elbow osteoarthritis.Material/MethodsPatients with moderate to severe CuTS secondary to osteoarthritis of the elbow were enrolled in our hospital from April 2015 to March 2018. Based on a previously proposed “elbow canal index”, a 1: 1 model of the elbow joint was printed using CT image data collected preoperatively. After computer-aided measurement, the standard for enlargement of the ulnar nerve groove was calculated and a personalized “trial model” was created by 3D reconstruction. After intraoperative exposure of the ulnar nerve sulcus, the proliferative osteoid was burred with a grinding drill, and the cubital enlargement was verified by the trial model. The ulnar nerve was decompressed and reincorporated into the enlarged cubital canal, and the Osborne ligament was zig-zag elongated and reconstructed.ResultsNone of the patients reported experiencing medial elbow instability, medial elbow pain, ulnar nerve subluxation, flexor-pronator weakness, or incision infection. There was significant improvement of the motor nerve conduction velocity, sensory nerve conduction velocity, two-point discrimination of the little finger, grip strength, pinch strength of the thumb and index finger, VAS score, and DASH score in this study (P<0.001).ConclusionsUlnar groove plasty guided by a 3D printing technique may be another effective treatment of moderate to severe CuTS caused by elbow osteoarthritis.

Rapid characterisation of the extremely large landslide threatening the Rules Reservoir (Southern Spain)

When an active landslide is first identified in an artificial reservoir, a comprehensive study has to be quickly conducted to analyse the possible hazard that it may represent to such a critical infrastructure. This paper presents the case of the El Arrecife Landslide, located in a slope of the Rules Reservoir (Southern Spain), as an example of geological and motion data integration for elaborating a preliminary hazard assessment. For this purpose, a field survey was carried out to define the kinematics of the landslide: translational in favour of a specific foliation set, and rotational at the foot of the landslide. A possible failure surface has been proposed, as well as an estimation of the volume of the landslide: 14.7 million m3. At the same time, remote sensing and geophysical techniques were applied to obtain historical displacement rates. A mean subsidence rate of the landslide around 2 cm/year was obtained by means of synthetic aperture radar interferometry (InSAR) and ground-penetrating radar (GPR) data, during the last 5 and 22 years, respectively. The structure-from-motion (SfM) technique provided a rate up to 26 cm/year during the last 14 years of a slag heap located within the foot of the landslide, due to compaction of the anthropical deposits. All of this collected information will be valuable to optimise the planning of future monitoring surveys (i.e. differential global positioning systems, inclinometers, ground drilling, and InSAR) that should be applied in order to prevent further damage on the reservoir and related infrastructures.

Research on Strong Ground Pressure of Multiple-Seam Caused by Remnant Room Pillars Undermining in Shallow Seams

Numerous room-and-pillar mining goaf are apparent in western China due to increasing small coal mining activities, which causes the collapse of the overlying coal pillars and the occurrence of strong ground pressure on the longwall face and surface subsidence. In this study, Yuanbao Bay Coal Mine, Shuozhou, Shanxi, was selected to study the collapse of the overlying coal pillars on the longwall face and reveal the mechanism of the pillar collapse and the disaster-causing mechanism caused by strong ground pressure. Results show that the dynamic collapse process of coal pillars is relatively complicated. First, the coal pillars on both sides of the goaf are destroyed and destabilized, followed by the adjacent coal pillars, which eventually cause a large-scale collapse of the coal pillars. This results in a large-scale cut-off movement of the overlying strata, and the large impact load that acts on the longwall face causes an unmovable longwall face support. Moreover, the roof weighting is severe when strong ground pressure occurs on the longwall face, causing local support jammed accidents. Furthermore, the data of each measurement point of the strata movement inside the ground borehole significantly increases, and the position of the borescope peeping error holes in the ground drill hole rise steeply. The range of movement of the overlying strata increases instantaneously, and the entire strata begin to move. Research on the mechanism of strong ground pressure can effectively prevent mine safety accidents and avoid huge economic losses.

Characteristics of Pressure Relief Gas Extraction in the Protected Layer by Surface Drilling in Huainan

To study the behavior of gas extraction from the protected layer by surface drilling, the common characteristics of gas extraction concentration and gas extraction quantity are summarized through the collection of key parameters of surface drilling and a combination of data and figures, with the background of 11−2 coal protection 13−1 coal in the Huainan mining area. The research results show that the flow of pressure relief gas extraction of the protected layer by surface drilling has three stages: a rising period, stable period, and decay period. When the extraction processes of multiple surface wells on the same working face are coordinated, the extraction flow is superimposed, and the extraction volume of surface drilling shows an increasing trend and fluctuates with the location of the drilling. The extraction flow rate before ground drilling is relatively small, and the extraction flow rate increases after ground drilling. This behavior is further confirmed by field observation of mining changes in the protective layer and the expansion and deformation of the protected layer. The periodic variation in the surface drilling and extraction quantity is affected primarily by the mining movement of the working face of the protective layer. Specifically, it is affected by factors such as the mining progress of the working face of the protective layer, mining height, degree of compacted goaf, degree of pressure relief of the protected layer, original gas content, and other measures taken to extract the protected layer.

BUSHEVE AND PISCHANA — HILL-FORTS OF POROSSYA DEFENSIVE LINE. TOPOGRAPHIC SURVEY AND STRATIGRAPHIC RESEARCHES

This paper presents the results of topographic survey, analysis of topography, current state of sites and gives an example of stratigraphic reconstruction of fortifications based on ground drilling. The main steps of the methodology of topographic survey and stratigraphic researches are highlighted.&#x0D; The closest hillforts to the Sukholisy one were documented by specialists of the Architectural and Archaeological Expedition of Institute of Archaeology during the campagne of 2020. The purpose of these works was to document the current state of sites and to prepare information for the conservation documentary.&#x0D; Busheve hillfort is similar to the Sukholisy one by its construction type and belongs to the early hillforts in the defensive line of Ros River area (Porossia). The study of this site is important for understanding the initial stage of the Old Rus settlement structure of Central Porossia region.&#x0D; Due to the stratigraphic research the cross-section of Busheve and Pishchana hillforts was reconstructed. Analyzing the information obtained from the ground drilling it is possible to make some conclusions for Busheve hillfort: 1) the defensive constructions of this hillfort were built in the river floodplain around a large dune; 2) the moat is traced only on one side; 3) drills 16—18 probably indicates the presence of archaeological layers appeared before the hillfort constructions.&#x0D; Conclusions by the results of drilling for Pishchana hillfort are the following: 1) the moat was made by deepening of the natural ravine; 2) the defensive wall has the traces of repair; 3) drill 11 found that on the edge of the hillfort the fortifications of World War II period were bult.&#x0D; The number of large-scale plans of Busheve and Pishchana hillforts were made with all the necessary descriptions and measurements with designation the constructions of the hillforts; stratigraphic researches; current state of hillforts; areas damaged by human activities. They are made for the preparation of conservation documentary.

A new stress-damage-flow coupling model and the damage characterization of raw coal under loading and unloading conditions

Coalbed methane, as a gas in coal seam, is a kind of potential clean energy with high reserves. At present, there are two main types of coalbed methane extraction in China, one is extracting coalbed methane by ground drilling, the other is coal and gas (coalbed methane) simultaneous extraction in coal mine underground. In the process of coal and gas simultaneous extraction, the migration of gas may not only cause coal and gas outburst, gas gushing and other disasters, but also cause the greenhouse effect. Therefore, in order to achieve the goal of safe simultaneous extraction of coal and gas and reducing greenhouse gas emissions, it is particularly important to understand the flow properties of gas and the damage characteristics of raw coal in the process of coal seam mining. In this paper, the mechanical properties and seepage characteristics of raw coal samples under loading and unloading conditions are studied experimentally by using the laboratory-fabricated ‘thermal-hydro-mechanical coupled with triaxial servo controlled seepage apparatus for gas-containing coal’. At the same time, X-ray tomography is carried out on the raw coal samples before and after the experiment. The deformation, damage and seepage characteristics of raw coal samples in the experimental process are recorded and analyzed. On the basis of the above, based on the information entropy theory, the change rate of information entropy is proposed as a damage characterization parameter, and its feasibility is verified by the comparison and analysis with the change rate of porosity. Finally, according to the basic definition of porosity, combined with statistical damage model, considering the gas adsorption expansion and Klinkenberg effect, the evolution model of permeability under loading and unloading conditions is developed. The model can better reflect the permeability evolution law of raw coal under loading and unloading conditions.

Environmental treatment technology for complex coalfield fire zone in a close distance coal seam—A case study

To achieve fast and effective control of complex coalfield fire areas in close-distance coal seams, proposals regarding “blocking air leakage, reducing oxygen, eliminating high temperature, and preventing re-ignition” were put forward. Combined with isotope radon measurement, infrared thermal imaging and ground drilling construction technology, the exact location of coalfield fire source was outlined. According to the characteristics of coalfield fire areas in Liujiamao and Qian’an mines, a set of economical and efficient coalfield fire control and extinguishing plans have been developed, which include the isolation of the production system, treatment of slope, injection of fly ash composite colloid, and excavation. The results show that the combined application of multiple detection technologies can accurately determine the location of fire source and divide three regions according to the temperature distribution. In addition, we developed a set of coalfield fire detection, fire-fighting equipment, fire-fighting materials and data monitoring as one of the coalfield fire control and extinguishing technology. Through the implementation of the plan, the coalfield fire disaster of Liujiamao and Qian’an mines was successfully solved. The successful application of this technology provides theoretical and technical support for similar coalfield fire control and extinguishing.

A history of Floral diversity (pollen, spores and algal) during the latest Holocene in the Bandung basin based on palynological analysis in Cihideung, West Java, Indonesia

Floral diversity is a measure of number of type flora in an area, and reflects how vegetation develops in response to the environmental condition during a certain time interval. The present study aims to examine changes in the diversity of vegetation (pollen, spores and algae), evenness, and similarity in the Bandung Basin through a core of 240 cm depth using a ground drill, as well as the radiocarbon dating (940 ± 120 BP) of a clayey peat level, located at the bottom (172.5 - 52.5 cm depth) of study section. Twenty four samples were taken at 5 cm intervals down the surface of the sediment core. Changes were obtained by comparing the quantity of pollen, spores, algae, and the lithology of the deposits. Palynomorph data show that Shannon diversity index ranged from 2.14 to 2.80 for pollen and spores, and 0 to 1.64 for algae; Shannon evenness index ranged from 0.64 to 0.81 for pollen and spores, and 0 to 1.74 for algae; and Jaccard similarity index results ranged from 30% - 68%. Faunal diversity is moderate with a good level of balance, and an overall trend in the increase of diversity in the clayey peat level. These changes are influenced by the presence of the Lembang Fault.

Redesign Mata Bor Tanah Untuk Pembuatan Lubang Biopori Di Desa Puron, Kecamatan Bulu, Kabupaten Sukoharjo

&lt;p&gt;&lt;em&gt;The lack of rainfall and the absence of catchment areas are the main factors of the lack of water in Puron Village. Making biopori becomes solutive because it is useful for water absorption, reducing standing water, composting containers, and fertilizing the soil. Artificial biopores are made by making holes in the ground using tools such as crowbars or using ground drilling machines. The use of aids model adapted to the drill bit based on the state of the soil contour. This research is focused on classifying drill bits and redesigning which is in accordance with the condition of the soil environment in Puron Village, Bulu District, Sukoharjo Regency. So that biopori holes can be created more effectively and efficiently. The research method was carried out through the classification of tool drill bits through the house of quality product (HOQ) and redesign using Autodesk Fusion 360 software application. It was found that the design with a screw drill model with a pointed spiral has a high product quality value and can applied in puron Village. The design of the drill bit by adjusting the contours of the Puron Village can make a 100 mm diameter biopori hole. The design specifications of the drill bit with steel cast with 12 spiral plates with a length of 1300 mm with a diameter of 115 mm can be driven with a 10 HP engine. The design results have maximum stress, displacement, reaction force and strain of 3.62 MPa, 0.00081 mm, 0.35 N, and 0.000015.&lt;/em&gt;&lt;/p&gt;

The Research of Coordination Extraction from the Stope Gas with Partition and Time-sharing

Based on the analysis of the distribution characteristics of the S-type overburden spatial crack field in a 3322 working face of a mine and the actual observations, it adopts comprehensive drilling modes such as ground drilling, high-drainage roadway drainage, and goaf buried pipe. “What time, where?” How much gas is extracted, and the effects of ground drilling, high-drainage roadway drainage, and underground pipe drainage in the goaf were evaluated, respectively, through space cracks in the S-type overburden The time-division extraction mode is adopted in the site, including comprehensive extraction methods such as high-draining lanes and buried pipes in the mined-out area. The gas extraction in the 3322 working face of the mine has reached the standard, ensuring safe and efficient mining at the working face.

An applied explicit mathematical model of conical drill point geometry without flank rubbing

Conical point drills are often used for making holes. In drill design, three drill point parameters, namely, drill point angle (or semi-point angle), chisel edge angle, and lip clearance angle, are specified. Geometrically, the conical point geometry is generated by two symmetric and oblique cones intersecting at the end of drill land. Thus, the drill point has to be designed in detail, which is to calculate the cone location and orientation parameters so that the drill point parameter values are equal to the specifications. Unfortunately, the previously proposed methods of drill point detailed design cannot be implemented in cutting tools companies, because one set of drill point parameter specifications can correspond to many sets of cone parameters which determine different drill point shapes. Moreover, the heel clearance flanks of some drills could rub stock material at the hole bottom while drilling, resulting in a large amount of force and heat, tool breakage, and severe wear. Drills with flank rubbing are invalid. However, the previous researches and applied industrial software cannot eliminate flank rubbing. To address the above problems, a practical and explicit mathematical model of conical drill point geometry without flank rubbing is established in this work. This work derives close-formed equations of the cone parameters and establishes a new criterion of flank rubbing detection. It can efficiently and consistently compute the cone parameters and detect flank rubbing for a valid drill point design. This explicit mathematical model is verified, and an approach to conical point detailed design is applied on two twist drills in the authors’ company. The differences between the drill point parameter values in the ground drill and the drill design parameter specifications are within an acceptable tolerance. Thus, the proposed method can be directly used in drill design and manufacturing in the tooling industry.

The Impact of Palm Oil Mill Wastewater on the Soil Properties of Paddy Fields

A paddy field is a wetland area which always muddy and constantly flooded by irrigation. This land possesses impermeable layers, hence the irrigation water quality ought to be maintained, to prevent changes in its properties, as well as the paddy field features. Furthermore, wetland pollution by the palm oil mill wastewater PT BSS was experienced in June 2018, characterized by a lowered quality of water in the fields of Manggopoh Village, Agam District, West Sumatra. The purpose of this study, therefore, is to determine the effect of PT BSS palm oil mill wastewater on the quality of paddy fields, using a survey method to obtain samples through random sampling techniques. This research was conducted downstream, based on the direction of flow along the irrigation channel as well as on the uncontaminated fields upstream. Furthermore, a ring and ground drill was used in the collection process, and analysis for physical and chemical properties was conducted in the Soil laboratory of the faculty of Agriculture, Andalas University. Subsequently, the evaluation involved averaging the soil data, followed by a comparison with the criterion level of damage, and ANOVA was used to estimate the difference between sample point locations, at a significance level of 0.05%. The results obtained indicate the absence of any changes in soil properties, in contrast with the water characteristics that can cause damage because the paddy soil is in a saturated state. Thus, wastewater is unable to permeate the soil matrix. Hence, it does not change the properties, since the values obtained passed the threshold criteria for soil.

The regolith properties of the Chang'e-5 landing region and the ground drilling experiments using lunar regolith simulants

The Chang'e-5 (CE-5) mission is China's first lunar sample return mission. The Rümker region in northern Oceanus Procellarum was selected as the landing area. CE-5 will automatically sample ~ 2 kg of lunar samples from the surface and subsurface. Previous studies focused more on the geological background of the landing region. However, the lunar regolith properties also have a significant influence on the mission, especially drilling, and thus should be studied and constrained. In this research, we analyzed the lunar regolith properties of the CE-5 landing region first using remote sensing measurements. The western maria and eastern maria in the landing region are both covered by very low-Ti to low-Ti basaltic regolith. The western mare regolith, with longer exposure to space weathering, is more mature, finer, and thicker than the eastern mare regolith. CUG-series lunar regolith simulants were then produced based on our analysis (physically and chemically) of the regolith properties of CE-5 landing region and compared to Apollo soils. Finally, the lunar simulants were used to perform ground drilling experiments to support the drilling of the CE-5 mission. In a fixed rotation speed (120 rpm), feed speed (120 mm/min), and total drilling depth (~1 m), 274, 291, and 346 g of lunar simulants were cored on simulants Mixture-1, Mixture-2, and Mixture-3, respectively. Our experiments suggest that it is easier to drill and core finer and looser lunar regolith. In this case, the western mare regolith is easier for drilling than the eastern mare regolith. However, samples from the eastern young maria (Em3, Em4) are scientifically more meaningful. We propose that landing on, and drilling in, a smooth and mature area in unit Em4 should be the highest priority for the CE-5 mission; this can be accomplished by careful landing site selection, precise landing and optimized drilling control.

Numerical Simulation of Parameters Optimization for Goaf Gas Boreholes

In view of the ground drilling of the N2206 working face in Shanxi Wangzhuang Coal Mine, the gas concentration is low and the extraction effect is not good. Fluent computational fluid dynamics software was used to simulate the ground extraction drilling position of the N2206 working face in the goaf (the distance from the top of the coal seam and the distance from the return to the wind). The numerical simulation results show that when the final hole of the ground extraction hole in the goaf is 16 m from the roof of the coal seam and the distance from the return air is 45 m, the extraction effect is optimal. The average extraction gas volume is 9.78 m3/min, and the average extraction gas concentration is 43.95%, the best extraction effect is obtained. After optimizing the ground drilling position in the goaf and combining with the site implementation, the maximum gas scouring amount of the extraction is 12.59 m3/min, which is 3.42 m3/min higher than the original. The maximum gas concentration of extraction was 63.54%, which was 28.82% higher than the original. After optimization, the gas concentration of the extraction is more than 30%, and the extraction effect is very good. Field application results further validate the reliability of theoretical analysis and numerical simulation results.

Modern drilling management system based on field data monitoring

Drilling engineering is technology-intensive and involves many subjects and large amounts of data. To improve the quality of production and management, decisions need to be made based on the latest data to direct the work on-site. Therefore, it is necessary to establish a safe, reliable, and efficient drilling management system that can meet daily production requirements. In this study, we describe a real-time monitoring system of field data. The system comprises real-time collection of borehole drilling parameters, ground drilling parameters, on-site video and borehole position data, and wireless data transmission to site and rear managers. The system is based on real-time monitoring of field data, the recognition and prediction of the conditions inside the borehole, the wireless transmission of data, and rear-base data analysis and feedback modules. The rear managers can view the real-time and historical drilling data at any time and compare and analyze drilling data by using the rear software of the management system to optimize the drilling program and feedback to the site. The application of the management system in production suggests that it can significantly improve drilling efficiency, reduce drilling costs and accidents in wells, and improve the automation of drilling operations. Moreover, at the same time, it can also predict complex conditions and drilling accidents in time and provide reliable real-time data to drilling technicians for on-site decision making.