Borehole Depth Research Articles

Chloride in the Chalk aquifer of East Anglia, UK, Part 1: Distribution of chloride in brackish and saline groundwater

The Chalk aquifer of East Anglia is heavily exploited as a groundwater source. During exploration and exploitation, it has become clear that some of the groundwater in the Chalk is brackish and unsuitable for drinking (>250 mg/l chloride). Data comprising chemical analyses of pumped water samples and borehole depth samples (> 900 results in total), and downhole geophysical surveys have been used to assemble maps of the distribution of chloride areally and with depth. Brackish or saline water is probably present at depth in the Chalk, even where shallow fresh water is present, over much of the area where Crag Group marine sediments have been deposited. The depth below surface at which brackish water is encountered varies between 50 to >100 m, and the elevation of the transition varies from +16 mAOD to below 91 mAOD. From its chemistry it is deduced that most of the brackish water is of ancient marine origin, but that there has been localised intrusion of modern seawater in coastal areas, especially around Ipswich. Saline water most probably entered the aquifer during Crag Group times (late Pliocene-early Pleistocene) and its chemistry has been modified subsequently. The most saline old water that has been encountered has full marine salinity.

A composite analytical model to predict the thermal performance of borehole ground heat exchangers within stratified ground

The thermal performance of borehole ground heat exchangers is of significance to the efficacy of the ground source heat supply systems. This paper presents a new composite analytical model to evaluate the thermal performance of borehole ground heat exchangers within stratified ground. The model integrates critical factors influencing heat transfer, encompassing ground stratification, thermal interactions among boreholes, variability of heat flux along borehole depth, and flexible layouts of boreholes. It enables efficient computation of thermal data pertinent to heat transfer both inside and outside the boreholes during operation. Implemented in the TRNSYS platform, the model offers versatile applicability to ground-source heat pump systems, borehole thermal energy storage, and district heating and cooling networks. Model validations were carried out through four distinct experiments, covering varied borehole quantities and ground conditions, to substantiate its accuracy. Employing this model, a case study further investigated the thermal performance of a borehole field with 16 boreholes in a three-layer ground (comprising backfill soil, clay, and fine sand) extending to a depth of 63 m. Over a 60-day warm water injection period at 30 °C, the effects of borehole layout and ground stratification on the thermal performance of individual and collective boreholes were analysed. Key findings in this analysis include: (1) Across the square, L-shape, and linear layouts, the impact of layout on the thermal performance of borehole fields diminishes as the spacing increases from 1 m, 2 m, and 3 m, becoming negligible at 4-m spacing, and the positions of the most and least affected boreholes by thermal interferences vary by layout; (2) Designing a GSHP system in stratified ground using a homogenous ground model with equivalent thermal properties would overestimate the heat injection performance of the borehole field and lead to undersizing of the borehole ground heat exchangers; and (3) ground stratification should be considered when estimating the thermal performance of a borehole field, particularly when the boreholes are sparsely arranged, e.g., with spacing of 3 m or more.

Heat Transfer Performance Factors in a Vertical Ground Heat Exchanger for a Geothermal Heat Pump System

Ground heat pump systems (GHPSs) are esteemed for their high efficiency within renewable energy technologies, providing effective solutions for heating and cooling requirements. These GHPSs operate by utilizing the relatively constant temperature of the Earth’s subsurface as a thermal source or sink. This feature allows them to perform greater energy transfer than traditional heating and cooling systems (i.e., heating, ventilation, and air conditioning (HVAC)). The GHPSs represent a sustainable and cost-effective temperature-regulating solution in diverse applications. The ground heat exchanger (GHE) technology is well known, with extensive research and development conducted in recent decades significantly advancing its applications. Improving GHE performance factors is vital for enhancing heat transfer efficiency and overall GHPS performance. Therefore, this paper provides a comprehensive review of research on various factors affecting GHE performance, such as soil thermal properties, backfill material properties, borehole depth, spacing, U-tube pipe properties, and heat carrier fluid type and velocity. It also discusses their impact on heat transfer efficiency and proposes optimal solutions for improving GHE performance.

Situational Analysis of Groundwater Resources in Kenyan Drylands, Case study of Turkana County

Recent climate changes have increased the incidences of severe droughts and floods, which have increased the vulnerability of pastoralists in the Kenyan drylands. Thus, there is a need to carry out a situational analysis of groundwater as it is the main source of water which provides baseline information useful for planning Analysis of results indicates that Turkana County is dominated by shallow wells and boreholes with the shallowest wells located along the seasonal rivers and Lake Turkana. The borehole depth was found to range between 20 to 200m. Most of the boreholes located near Lake Turkana were shallower compared to those far away from the lake with a depth ranging between 0 to 52m. Most of the boreholes had a low yield that ranged between 1.2 to 4.6m3/hr be attributed to the basement rocks which are prevalent in the county and are classified as poor aquifers. The water points were mainly dense in urban areas, which was mainly the central region where the water demand was high and this was attributed to the high population. The groundwater levels occurred mostly at 13m indicating that Turkana County has mostly shallow aquifers that predominantly occurred along the river valleys and at the edge of the volcanic deposits. The groundwater quality is mainly saline as most of the boreholes had high TDS, EC and chloride levels. The presence of high fluoride levels indicates the presence of high volcanic rocks that have high fluoride ions that are largely prevalent in the study region. The Sulphate, Nitrite and Nitrate Levels in all the water samples analyzed were below the EU, WHO and KEBs standards indicating the low anthropogenic activities carried out in the drylands as most farmers are pastoralists. The most prevalent cation was sodium in some of the boreholes indicating why the groundwater was saline.

One-Dimensional Electrical Resistivity Prospecting for Small Dam Projects: A case Study Smaquli Dam, East Erbil City, Kurdistan Region of Iraq

Abstract: This study employs the One-Dimensional Vertical Electrical Resistivity technique to elucidate the subsurface stratigraphy and structures beneath the axis and abutments of the suggested Smaquli dam, situated to the east of Erbil City in Kurdistan Region of Iraq (KRI). Three traverses were conducted using a Schlumberger array. Data interpretation was performed using the Russian commercial software, IPI2WIN. Each measurement point featured a maximum total electrode spread ranging from 400-600m, reaching an investigation depth of 130m to 150m. The inter-distance between successive measurement points varied from 16m to 17.5m. Geo-electrical sections were generated by interpreting the data, revealing three distinct lithological groups: alluvial deposits (upper first group) with a thickness ranging from 3 to 10 meters, marl and marly limestone of the Shiranish Formation (second group) with thickness ranging from 18 up to 110 meters, and dolomitic limestone of the Bekhme Formation (third group) which its thickness is not defined. These lithological groups exhibited significant resistivity contrasts, rendering the resistivity method effective for delineating their interfaces. The resistivity of the upper horizon ranged from 18 to 136 Ω·m, the second horizon exhibited values between 19 and 304 Ω·m, while the lower third horizon showed high resistivity values ranging from 97 to over 50000 Ω.m.. The relatively low resistivity values of the lower horizon (Bekhme Formation) are interpreted as fractured and water-saturated limestones, whereas the high values are indicative of bituminous material. A correlation was established between the geo-electrical sections and borehole geologic columns, demonstrating consistency in indicating the presence of two rock units within the uppermost 20m, which corresponds to the borehole depth.

DEVELOPMENT OF PEAK GROUND ACCELERATION USING A NON-LINEAR APPROACH TO EVALUATE LIQUEFACTION POTENTIAL IN SEI WAMPU BRIDGE, LANGKAT, NORTH SUMATRA, INDONESIA

The design of building structures requires compliance with seismic codes and all their consequences. Based on geotechnical investigation reports, the construction of Sei Wampu Bridge in Langkat, North Sumatra, Indonesia, is located in an area where the soil layers are predominantly sand with shallow water levels because of its proximity to a river and is a high earthquake zone due to the Semangko fault. That condition will affect the potential of liquefaction occurring. This study aims to identify the liquefaction potential in the Sei Wampu Bridge. Based on Indonesian National Standard (SNI) 1726-2019, sites prone to liquefaction are categorized as site class-specific soil (F) and requires site-specific response analysis (SSRA) methods. Non-linear analysis 1-D is chosen to propagate earthquake waves with the software DEEPSOIL V7. The input parameter for soil movement utilizes an average spectral matching method with a minimum of 7 pairs of soil movement selected from the earthquake recording website, PEER Ground Motion Database. The selection of earthquake considers a 1000-year earthquake load return period, or a 7% probability exceeded within 75 years. Site-specific response analysis (SSRA) resulted in a peak ground acceleration (PGA) value for each borehole depth used in liquefaction potential analysis. Using a historical earthquake scenario with a 6.3 Mw shows that the research location has liquefaction potential at 0 m-15 m deep with high vulnerability levels, where the LPI value reaches 36.21.

Analytical model development for vertical medium/deep ground heat exchangers with U-tube(s)

The U-shaped ground heat exchanger (UGHE) offers an effective solution for building heating and cooling purposes. In the practical applications of vertical UGHEs, the borehole wall temperature varies along the borehole depth due to the uneven initial ground temperature and transient heat transfer process. The assumption of a uniform temperature along the borehole wall in the existing quasi-3D model of UGHE causes a non-negligible error in the calculation of fluid temperature, especially for the cases of shallow-medium boreholes. Thus, two new analytical models are established to calculate the fluid temperatures for the single U-shaped GHE (1-UGHE) and double U-shaped GHE (2-UGHE), considering the depth-dependent borehole wall temperatures. The convolution theorem is employed to solve the mathematical problem of the nonlinear condition on the borehole wall, and the Laplace transformation is used for getting the final temperature expressions. The new analytical models are compared and verified by the on-site experiments. The results show that the two models exhibit promising prediction accuracies and similar variation trends in fluid temperatures. Then, parametrical and economical analyses for 1−/2- UGHEs have been carried out. Finally, the geographical thermal potentials of 1−/2- UGHEs across China have been comparatively investigated and the corresponding thermal map-based application potential recommendations have been given.

Simulation study on the radioactive logging responses in the spiral borehole

Abstract The spiral borehole, primarily attributed to uneven force on the drill bit, poses a unique drilling and well logging challenge. In certain logging applications, this phenomenon can disrupt logging responses, introducing periodic fluctuations in the logging curve and complicating the interpretation process. To elucidate the impact of the spiral-borehole phenomenon on conventional radioactive logging methods, we conducted a simulation study examining its effects on traditional density tool, thermal-neutron porosity tool, and natural gamma tool. Our findings reveal significant influences on density and porosity tool responses, with the amplitude of periodic fluctuations in logging curves closely linked to the groove depth of the spiral borehole. Conversely, the natural gamma tool exhibits minimal impact, with noticeable spiral-borehole effects causing limited fluctuations. Additionally, when the groove depth of the spiral borehole is fixed, the smaller the distance between the logging tool and the well wall, the closer the value obtained by the logging tool is to the true value of the formation parameter, and vice versa. This research offers theoretical insights for effectively correcting spiral-borehole effects in radioactive logging methods.

Thermal response tests on boreholes in multi-layered ground with geothermal gradient

The design of ground source heat pump systems requires knowledge of the properties of the ground and boreholes, which are often measured through thermal response tests (TRTs). Conventional TRT analysis methods apply for uniform ground properties and undisturbed ground temperature. These assumptions become less valid for deeper boreholes, which penetrate more ground layers while the geothermal gradient becomes more important. In multi-layered ground without a geothermal gradient, conventional methods estimate the effective ground thermal conductivity kgr near the thickness-weighted average, but a geothermal gradient adds complications. In the present study simulated TRTs with quasi-steady-state and fully transient models demonstrate that the required test duration for conventional methods may become impractically large as the borehole depth increases. In general, this occurs when the dimensionless parameter |qratio| approaches 1 or less. This parameter represents the ratio of the externally imposed heat injection/extraction rate to the natural heat rate associated with the geothermal gradient. In these cases, the conventional methods do not estimate the thickness-weighted average value of kgr. On the other hand, a fully transient multi-layered ground model can determine the thickness-weighted average value of kgr. This model requires measured fluid vertical temperature profiles to estimate individual layer values of kgr within reasonable uncertainties.

Study on the Operation Optimization of Medium-Depth U-Type Ground Source Heat Pump Systems

Deep geothermal energy is a sustainable and renewable spacing heating source. Although many studies have discussed the design optimization of deep borehole systems, few have accomplished optimization and in-depth analysis of system operation control. In this study, an analytical model of the U-type deep borehole heat exchanger is proposed, and the average relative error between the simulated outlet temperatures and experimental data is −3.2%. Then, this paper presents an integrated model for the operation optimization study of the U-type deep-borehole ground source heat pump system. The optimal control of flow rate is adopted to match the variation in heating load. Compared with the constant-flow rate (110 m3/h) operation mode, the variable flow rate method reduces the power consumption of the heat pump and circulating pump by 22.1%, from 288,423 kW·h to 224,592 kW·h, during 2112 h of operation. In addition, the system has a larger RHS and COP when the thermal conductivity of the backfill material increases. When the borehole depth increases by 200 m from 2300 m, the energy consumption of the circulating pump will drop from 85,844 kW·h to 56,548 kW·h. The COP of the heat pump unit will decrease approximately linearly as the heating load increases, and the total power consumption will increase accordingly. This work can provide guidance for the design and optimization of U-shaped GSHP systems.

Spatial occurrence and variation of the active pharmaceutical compounds in rivers and groundwater systems in Arusha City, Tanzania

This study investigated the occurrence of 11 pharmaceutical compounds in the rivers and groundwater systems of Arusha City, Tanzania. Each suspected individual residue of active pharmaceutical compounds in water matrices, was pre-concentrated using solid-phase extraction techniques and, then quantified using a liquid chromatography-mass spectrometer mass spectrometer (LC-MS/MS). The concentrations varied across the assessed rivers and groundwater systems. High concentrations of caffeine 520 ng/L were detected in the station downwards of a wastewater stabilization pond, discharging its partially treated effluent into the river, followed by stations whose rivers flowed through informal areas. Sampled points' located near the river's water sources reported fewer compounds with values below the detection limit, such as amoxicillin, paracetamols, and doxycycline. Except for sulfamethoxazole (94 ng/L) in the borehole, most of the concentrations detected in rivers were ten times higher than in boreholes. In addition, in boreholes, more compounds were identified in the monitoring than in the domestic ones, and concentration varied with depth of deep boreholes (25 m) were less abundant than shallow wells of less than 10 m. In conclusion, pharmaceutical compounds were frequently detected in both rivers and groundwater systems within Arusha City suggesting the need for understanding of their fates and associated risks.

Analysis of the Combined Effect of Major Influencing Parameters for Designing High-Performance Single (sBHE) and Double (dBHE) U-Tube Borehole Heat Exchangers

In this paper, a comprehensive analysis of the combined effect of major influencing parameters on heat transfer in a single U-tube BHE (sBHE) and a double U-tube BHE (dBHE) with two independent circuits was performed by using a validated numerical heat transfer model. Geometrical parameters, such as shank spacing (with maximum, average, and minimum values), borehole diameter (large, medium, and small borehole sizes), and borehole depth (shallow, average, and deep borehole depths) as well as the thermal conductivity of soil and grout, which ranges from minimum to high values, were considered. The combined impact of these parameters was included under the following four major cases: (1) the combined effect of borehole depth, borehole size, and shank spacing; (2) the combined effect of borehole depth and soil and grout thermal conductivity; (3) the combined effect of soil and grout thermal conductivity and borehole size; and (4) the combined effect of soil thermal conductivity, borehole size, and shank spacing. Each of these major cases has nine different design options for both sBHEs and dBHEs. A series of results of heat transfer per unit borehole depth were generated for all the considered various cases. With the given parameters, the BHE case that provides the highest heat transfer among the various cases of sBHEs and dBHEs were obtained.

Influence of heat storage on performance of multi-borehole mid-deep borehole heat exchangers

Storing heat underground is an effective method to solve the problem of apparent ground temperature decrease due to long-term operation of a multi-borehole mid-deep borehole heat exchanger (MMBHE), which will cause heating capacity decrease and even heating failure. To understand the influence of heat storage on the MMBHE operation performance, based on the proposed model considering heat storage and extraction, this research comprehensively analyzes the influence of heat storage on the MMBHE heat extract capacity, ground temperature distribution, fluid temperature variation along flow path. The influential factors analyzed include borehole layout, borehole amount, borehole spacing, and borehole depth. The results indicate that adopting heat storage in non-heating seasons significantly improves the ground temperature and the heat extraction capacity of the MMBHE. The MMBHE can extract more heat with heat storage than that without heat storage when the heat storage fluid temperature is higher than the critical heat storage temperature which is much less the borehole bottom temperature. As the case discussed in this paper, the mean heat extraction capacity with heat storage is 24.25 % higher than that without heat storage. As the borehole depth increases, there is a substantial increase in the heat extraction capacity of the MMBHE with no heat storage, and the heat storage effect is weakened when heat storage adopted in non-heating period. Less borehole number and larger borehole spacing make larger mean borehole heat extraction capacity of an MMBHE with no heat storage. However, when the borehole layout, borehole amount, borehole spacing, and borehole depth change, fluctuation of the mean borehole heat extraction capacity with heat storage is much smaller compared to those with no heat storage. When the borehole spacing increases from 25 m to 45 m with no heat storage, the mean heat extraction capacity of the MBHE is increased by 27.67 kW, while that is 11.88 kW with heat storage. This research can provide some inherent understanding of the heat storage on MMBHE performance and reference for designing MMBHE with heat storage systems.

Comparative Analysis of Influencing Factors on Heat Extraction Performance of Multi-Type Shallow Borehole Heat Exchangers

In this paper, the influence of design parameters and geological parameters on the heat extraction capacity of common coaxial type, single U-type, and double U-type borehole heat exchangers(BHEs) in shallow ground source heat pump system is analyzed, and the heat extraction performance of different types of BHEs is further compared. The results show that with the increase in borehole depth and ground temperature gradient, the outlet temperature of the three types increases at the end of the heating season, and the single U-type BHE increases most significantly. The increase in inlet flow rate will decrease the outlet temperature of the three BHEs, and the U-type is the most obvious decrease. The increase in inlet temperature will reduce the temperature difference between inlet and outlet of the three types BHEs. Given the same design parameters, coaxial-type BHE obtains the maximum heat.

Anchorage performance of a new rebar bolt under different surrounding rock strength and borehole depth

The theory and technology of rock bolting are fundamental research topics for strata control in civil and mining engineering. Rebar bolts are commonly used for roadway primary support in underground coal mine. To adapt to deep resource mining, a new left threaded rebar bolt has been developed. Compared to conventional rebar bolts, the result of installation test showed that the new bolt reduced of 41.5% and 57.9% in stirring resistance force and torque, respectively. In laboratory pullout tests, PVC and aluminum sleeves were used to simulate weak and medium strength surrounding rocks. The average peak pullout force, displacement at the peak load and energy absorption increased by 27%, 107% and 108%, respectively, using PVC sleeve; and increased by 113%, 109% and 212%, respectively, using aluminum sleeve. Field tests were conducted under soft coal, hard coal and medium strength rock geo-conditions. Different borehole depths were selected to precisely calculate the average anchorage performance of the new bolt. Results showed that the average peak pullout force of the new bolt increased by 37%, 38% and 28%, respectively, under different surrounding rock conditions. Moreover, based on on-site test results, the pullout curves in field-testing were summarised and classified into 6 different patterns, which were discussed from a viewpoint of causality mechanism. The research findings validate that the newly developed bolt has better anchorage performance compared to conventional rebar bolts, making it a new anchorage material for deep resource mining.

Using sectional blasting to improve the efficiency of making cut cavities in underground mine workings

Introduction: The research concerns how making cut cavities improves drilling and blasting operations as well as the optimum parameters to arrange both snubber and auxiliary blastholes.Methods: The research methods include experimental and industrial activities to identify the optimum depth of the first-section snubber blastholes relative to the second-section blastholes. It also identifies optimum parameters of the snubber blastholes while driving mine workings and ore breaking in stopes with different mine working sections and different rock mass strengths broken using the technique of cut-cavity formation.Results and Discussion: Experimental explosions executed in a production environment have proved the efficiency of the proposed technique of sectional formation of a cut cavity, which helped increase the blasthole use coefficient (BUC) from 0.88 to 0.97. The depth of the first-section boreholes should be determined relative to the length of the second-section boreholes and the broken rock mass strength. The higher the strength of the broken formation, the larger the ratio between the first and the second-section blasthole lengths should be. The results of the experimental explosions indicate that the depth of first-section snubber blastholes varies from 0.5 and more of the second-section boreholes, depending upon the depth of the latter and the broken rock mass strength. If the strength of the broken rock mass is 12 on the Protodyakonov scale, and the second-section blasthole depth increases from 1.6 m to 2.6 m, then the depth of the second-section boreholes should be increased from 0.9 m to 1.54 m so as to be 0.55–0.56 of the second section blasthole length. If the strength of the broken rock mass is 18, and the length of the second section increases from 1.8 m to 2.82 m, then the first-section length varies from 0.9 m to 1.75 m, being 0.5–0.62 of the second section blasthole length. Applying the novel proposed procedure for a cut-cavity formation will increase the blasthole use coefficient and reduce the cost of drilling and blasting operations. Moreover, the procedure may also be practical for driving underground mine workings and for ore breaking within stopes.

EXPERIMENTAL STUDY ON CREEP LOADING OF POROUS COAL UNDER DIFFERENT INFLUENCING FACTORS

After the gas drainage borehole is formed in the coal seam, its stress deformation process is a creep process without the influence of mining. By arranging boreholes on coal samples and carrying out creep loading test of porous coal through rock mechanics testing machine, the creep process of boreholes in actual coal seams is simulated. The results show that the creep loading test results of drilled coal are quite different from those of conventional loading. Creep loading produces large deformation due to rheological and aging characteristics. Compared with non-porous coal, the yield of drilled coal occurs earlier and the yield platform is wider during creep loading. Also, the larger the borehole diameter, the deeper the borehole depth, and the lower the peak stress. The up dip angle is easier to destroy than the down dip angle. Compared with hard coal, soft coal produces greater deformation under smaller peak stress. The research results have guiding significance for drilling gas drainage in the soft coal seam.

Advanced machine learning techniques: Forecasting thermal resistance in borehole heat exchanger system through RSM and hybrid DFNN-GA approaches

The thermal efficiency of ground heat exchanger (GHEs) relies on optimizing borehole thermal resistance and total internal thermal resistance for cost-effective and efficient design. This study aims to establish a robust correlation among various parameters, including thermal conductivity of pipe, grout, and ground, borehole depth, borehole and pipe diameter, pipe-pipe distance, fluid velocity, and heat transfer rate of the ground, with the 3D borehole thermal resistance (Rb,3D) and total internal thermal resistance (Ra,3D). This exploration of eight influential factors results in an l-130 design matrix with 130 data points. A 3D computational model, utilizing a four-resistance method, accurately calculates Rb,3D and Ra,3D, while analyzing heat transfer in both solids and fluids. Two prediction models, Response Surface Methodology (RSM) and a hybrid Deep Feedforward Neural Network-Genetic Algorithm (DFNN-GA), establish the correlation between Rb,3D and Ra,3D and the eight variables. The results highlight the efficacy of the prediction models, achieving R2 values of 79.87% and 87.90% for RSM and 94.00% and 99.15% for DFNN-GA, corresponding to the predictive accuracy of Rb,3D and Ra,3D, respectively. Furthermore, lower RSME, MAE, and AARE values are observed. A rigorous comparative analysis assesses the relative effectiveness of these methodologies in achieving the research goals.

Investigation on the influence of mixed borehole depths in vertical ground heat exchanger systems

Most studies about vertical borehole heat exchangers (BHEs) tended to focus on optimizing total borehole length with all boreholes having the same depth. This is mainly because most of the vertical BHEs design tools do not have the feature of designing mixed borehole depths at the same bore field. Because thermal saturation occurs over time at the center of the field due to thermal interaction between the confined boreholes in the interior region, reducing depth of these less efficient boreholes is a desired goal. This paper studies the effects of mixed borehole depths where shorter boreholes are designed to be in the interior region, and deeper ones in the perimeter. The python package pygfunction has been adapted in this paper to generate the thermal response factor of a bore field with mixed borehole depths and to simulate its performance in difference design scenarios. The results reveal that total BHE-length could be decreased by up to 10 % in some cases of mixed borehole depths compared with the case of same-depth boreholes. However, since the total BHE-length could increase in few cases, careful examination is crucial when applying mixed borehole depths.

Borehole Depth Recognition Based on Improved YOLOX Detection

Abstract This study proposes a method for recognizing the drill depth in low-light underground environments, with the aim of addressing the issues of low efficiency and susceptibility to manual changes in the current methods. The method is based on an improved You Only Look Once X model. Initially, image data undergo enhancement and annotation. Secondly, it incorporates an attention mechanism to improve the feature extraction capability. The feature pyramid is utilized to minimize feature loss and facilitate better multi-scale feature fusion. Additionally, the loss function is optimized to enhance the localization ability of the prediction box. The enhanced model achieves an accuracy of 91.3$\%$, representing a 4.4$\%$ increase compared to the pre-improvement performance, and demonstrates improved positioning accuracy. Successful drilling depth measurements were carried out with the acquired positioning information.