Natural Gas Transportation Research Articles

A Study on the Erosion Mechanism of an Axial Cyclone Separator for Gas Purification

Severe erosion occurs in the cone bottom and the joint part between the cone and cylinder of the cyclone separator used in high-pressure natural gas transportation. The main objective of this study is to reveal the mechanism and influencing factors of erosion. To address these issues, the numerical simulations were used to investigate the parameters, such as inlet gas velocity, particle concentration, particle size, the cone length, the diameter of dust exit and the vortex finder. The results indicate that wall erosion is significantly affected by the inlet gas velocity and particle diameter. Increasing the cone length and the dust exit diameter can effectively reduce wall erosion, whereas the cyclone separation efficiency would be reduced simultaneously. It is worth noting that the vortex finder with spiral slits is of benefit to increase the cyclone separation efficiency but decreases the maximum erosion rate of the cyclone cone by at least 80%.

Nondestructive testing and 3D imaging of PE pipes using terahertz frequency-modulated continuous wave.

Polyethylene (PE) pipes are widely used as the main carrier for the transportation of natural gas, so nondestructive testing techniques for PE pipes are essential for the safety of natural gas transportation. In order to compensate for the shortcomings of conventional inspection methods, a terahertz (THz) three-dimensional imaging system for nondestructive inspection of PE pipes is designed. The system is based on frequency-modulated continuous-wave (FMCW) technology, with a THz source bandwidth of 0.225-0.330THz and an output power of over 5mW, which can achieve submillimeter spatial resolution in three dimensions. The system is used to scan PE pipes in three dimensions in a laboratory environment, and the results show that the system could achieve nondestructive testing and three-dimensional imaging of different defects in PE pipes. In addition, combined with the deep-learning-based THz transformer network, the intelligent identification of different defects is realized, and the accuracy rate can reach up to 88%. The above results provide technical guidance for the application of THz FMCW systems in the actual detection of PE pipes, and provide supplements and improvements for traditional detection methods.

Research on wet gas separation method based on swirl and ejection cycle technology

Gas-liquid co-production often occurs in the middle and late stages of natural gas production. Efficient wet gas separation is very important in natural gas transportation and measurement. The traditional separation device has a relatively low separation efficiency due to the flow patterns, a new type of pipe separator was designed based on the swirl and ejection cycle technology. A new systematical separation procedure with three main steps was proposed simultaneously. The wet gas was forced to form an annular flow by a swirler. Then, the liquid film flows into the annular gap. The wave layer was introduced into the swirl separation again with the self-circulating ejection system for fine separation finally. Laboratory experiments and Computational Fluid Dynamics (CFD) simulations show that the additional swirl process can decrease the flow pattern influence effectively, and the separation efficiency can increase to more than 90%. The separation efficiency is mainly determined by the gas superficial velocity, and while the velocity of the inlet gas is less than 21 m/s, the separation efficiency is up to 93%. The separation efficiency prediction model was established based on liquid film porosity, and the prediction relative error is less than 10%. The new device, the separation procedure, and the test results can provide constructive technical reference for the real-world pipe separator application.

Optimizing the environmental sustainability of alternative post-harvest scenarios for fresh vegetables: A case study in Spain

The aim of this research is to define different scenarios that optimize the environmental sustainability of the post-harvest stage of vegetable products (cauliflower and brassicas mix). These scenarios considered different packaging materials; energy generation technologies for the processing plant (standard electricity mix vs. renewable options); organic waste management (composting, anaerobic digestion, and animal feeding); and refrigerated transportation (local, national, and international, using diesel, natural gas, and hybrid trucks and railway). The analysis has been carried out based on a foreground inventory provided by a company that operating internationally, in accordance with the International Organization for Standardization (ISO) 14,040 methodological framework and following the latest Product Environmental Footprint (PEF) protocols. The analysis describes four midpoint categories, single score (SS) using EF3.0 life cycle impact assessment (LCIA) methodology and the Cumulative Energy Demand. The carbon footprint (CF) of the post-harvest stage for a base case scenario ranged between 0.24 and 0.29 kg CO2 eq/kg of vegetable, with a strong contribution associated to the production of packaging materials (57.8–65.2 %) and the transport stage (national range in conventional diesel vehicles) (31.5–38.0 %). Comparatively, lower emissions were associated with the energy consumed at the processing factory (up to 4.1 %) while the composting of organic waste management produced some impact savings (up to −3.5 %). Although certain differences were observed, the dominance of the transport stage and the packaging materials is sustained in all the other environmental impact and energy categories evaluated. The most effective measures to reduce the environmental footprint of the post-harvest stage involve: i) using reusable packaging materials; ii) reducing the transport range and using vehicles running on natural gas or hybrid technologies; iii) the incorporation of renewable energy to supply the factory; and iv) the utilization of the organic residues in higher value applications such as animal feeding. Implementing the measures proposed in this study would reduce the post-harvest CF of fresh vegetables by 90 %.

A novel study on bypass module in self-regulated pipeline inspection gauge to enhance anti-blocking capability for secure and efficient natural gas transportation

Bypass pigging technology is an emerging strategy with promising potential to reduce the velocity of pipeline inspection gauge (PIG) and mitigate pigging-induced slug volume for oil and gas transportation systems. Nonetheless, the critical issue of bypass pigs being blocked in pipelines is a major concern for wide implementations of this new technology. To this end, this study newly proposes an intelligent self-regulated bypass pig prototype by developing an internal bypass regulating module to enhance the anti-blocking capability for pigging operations. To facilitate the optimal design of the bypass regulating module, force variation characteristics of the bypass valve in blocked bypass pigs are of great significance. Accordingly, this study thoroughly investigates bypass valve forces for bypass pigging under the blockage status both experimentally and numerically. The experimental results show that an increase in gas velocity can almost linearly increase the valve force, which is mainly affected by the driving gas flow rate. Specifically, when the gas velocity increases from 1.26 to 4.4 m/s, the valve force can be increased from 1.46 to 12.88 N on average. In addition, a CFD-based numerical model was developed and experimentally validated to calculate valve forces. The numerical model, which has the mean bias error below −0.886 N with the index of agreement over 0.98, can be used as an effective approach to valve force analyses. Finally, the optimal design scheme for bypass pigging with anti-blocking capability was proposed, which can considerably facilitate the secure and efficient pigging performance and natural gas transportation.

Enhanced anti-microbial corrosion of nano-CuO-loaded Ni coatings on pipeline steels in simulation environment of natural gas transportation pipeline

Bacteria were introduced into natural gas transportation lines and reacted with CO2 and corrosive ions to cause severe corrosion when natural gas was captured by water drive methods. Anti-microbial corrosion of natural gas pipeline is an important prerequisite for pipeline steel protection. An Ni coating with high corrosion resistance was prepared on the surface of pipeline steel by electrodeposition method, and CuO nanoparticles were introduced to obtain anti-microbial function. A simulated corrosion environment in a natural gas pipeline was designed to investigate the corrosion resistance behavior of the CuO-loaded Ni coating under the combined action of CO2, Cl−, and sulfate-reducing bacteria (SRB) and the inhibition effect of CuO on the microbial corrosion of SRB. The corrosion rate of nano-CuO-loaded Ni coatings at 15 days was only 41.8% of that of the pipeline steel. In addition to the corrosion resistance of the Ni coating, the corrosion rate was reduced because nano-CuO reduces the probability of corrosion reactions and has an anti-microbial effect on SRB. This coating with anti-microbial and anticorrosive functions has important engineering application value for the microbial corrosion protection of natural gas pipelines.

Enhanced clathrate hydrate formation at ambient temperatures (287.2 K) and near atmospheric pressure (0.1 MPa): Application to solidified natural gas technology

Solidified natural gas is a promising alternative for improving natural gas storage owing to its safe and environmentally friendly properties. However, harsh conditions limit its application. In this study, the R141b was used as a thermodynamic promoter to enhance methane hydrate formation under mild conditions. Addition of R141b to the water system significantly shifted the phase equilibrium boundary to lower pressures and higher temperatures, in which the R141b-CH4 hydrate can be formed at 0.1 MPa and 287.2 K. Notably, the final pressure of the cell after hydrate formation was near the atmospheric pressure even at an initial pressure of 5.384 MPa, suggesting that the R141b-CH4 mixed hydrate had milder storage conditions and lower costs than liquefied natural gas (approximately 110 K). The higher initial pressure significantly reduces the induction time and increases gas storage. The mechanism of unusual kinetic characteristics of the R141b-CH4 hydrates that were observed can be attributed to the different nucleation behaviour of CH4, R141b, and R141b-CH4 hydrates. This study provides evidence of a new promoter using the solid hydrate method under mild conditions that can be alternatively used for the storage and transport of natural gas, thereby increasing the supply of clean energy without the high economic costs and safety issues.

Stress Shifting Effect of Hydrogen Mixed Natural Gas Pipe Under Seismic Wave

Abstract Hydrogen energy is a kind of clean secondary energy sources. Mixed hydrogen natural gas transportation technology is a new scheme of hydrogen transportation. Using natural gas pipe to transport hydrogen is expected to further promote its application. In order to study the mechanical properties of buried steel pipe under seismic waves, a numerical model is established. The time history and stress distribution of pipe section under seismic wave are analyzed. Effects of seismic intensity, surrounding soil, buried depth and seismic wave type on pipe's mechanical properties are discussed. The results show that the pipe section stress fluctuates under seismic wave, and the stress shifting effect occurs. The maximum stress is located in the directions of 45 deg, 135 deg, 225 deg, and 315 deg. Stress increases with the increasing of seismic intensity, and the stress distribution of pipe section is also changed. Stress responses of the pipe in different soil are different, and the stress distribution of pipe section at the maximum stress time is similar. The deeper the buried depth is, the greater the pipe stress is. Pipe stress is related to the maximum acceleration of the seismic wave and spectrum characteristics. Those results can provide a basis for the design and safety evaluation of mixed hydrogen natural gas pipes.

Kármán Vortex Street Driven Membrane Triboelectric Nanogenerator for Enhanced Ultra-Low Speed Wind Energy Harvesting and Active Gas Flow Sensing.

Wind energy harvesting and sensing have a huge prospect in constructing self-powered sensor nodes, but the energy transducing efficiency at low and ultra-low wind speeds is still limited. Herein, we proposed a Kármán vortex street driven membrane triboelectric nanogenerator (KVSM-TENG) for ultra-low speed wind energy harvesting and flow sensing. By introducing Kármán vortex in the KVSM-TENG, the cut-in wind speed of the KVSM-TENG decreased from 1 to 0.52 m/s that is the lowest cut-in wind speed in current TENGs. The instantaneous output density of the KVSM-TENG significantly increased by 1000 times and 2.65 times at the inlet wind speeds of 1 and 2 m/s, respectively. In addition, with the excellent energy transducing performance at the ultra-low speed range, the KVSM-TENG was successfully demonstrated to detect a weak leakage of gas pipeline (∼0.6 m/s) for alarming with high sensitivity. The interaction mechanism between the vortex and KVSM-TENG was systematically investigated. Through the simulation and experimental validation, the enhancement mechanism of vortex dependence on the cylinder diameter and placement location of KVSM-TENG was investigated in detail. The influence of parameters such as membrane length, width, thickness, and electrode gap on the performance of the KVSM-TENG was systematically studied. This work not only provided an ingenious strategy for ultra-low speed wind energy harvesting but also demonstrates the promising prospects for monitoring the air flow in the natural gas exploitation and transportation.

Numerical Investigation of the Strain Characteristics of a Natural Gas Transportation Pipeline Crossing Tunnel

To ensure the safe operation of a natural gas transportation pipeline (NGTP) crossing tunnel, a model is established to analyze the strain characteristics. Some factors affecting the strain are considered in this paper. The results show that the strain failure of a NGTP crossing tunnel may occur in the two elbows of the NGTP located at the tunnel entrance and the position in contact with the fixed pipe clamp near the tunnel entrance. At the same time, the strain of the NGTP crossing tunnel is obviously affected by the temperature change of natural gas. So, the temperature change should be controlled within 8 K in the actual operation process. The wall thickness, the length of the NGTP, and the slope angle of the crossing tunnel are also main factors to affect the strain of the NGTP crossing tunnel, while the operation pressure and mountain slope angle have little effect when the operation pressure is 6–11 MPa. The maximum value of Mises equivalent strain is also obviously affected by the pipe diameter when it is more than 273 mm. Meanwhile, a prediction model for the maximum value of Mises equivalent strain is also established by the nonlinear fitting method and the deviation is within ±15% between the calculations and simulation results. The above conclusions will provide a theoretical basis and data support for the safe operation and design of NGTP crossing tunnels.

Assessment of the mass burning rate of LNG pool fires by a validated CFD model

Liquefied natural gas (LNG) is widely used, because it provides an easy and economic solution to the transport and storage of natural gas (NG), especially on long distances or when transport by pipeline is not viable. The LNG pool fire is one major process safety accident at the LNG facilities according to the report of the U.S. Government Accountability Office. Moreover, due to the high surface emissive power of LNG compared to other hydrocarbon fuels, LNG pool fires have a high potential in causing domino effects and cascading events in process industry. Previous studies developed Computational Fluid Dynamics (CFD) models of LNG pool fires, but the mass burning rate was fixed manually as a model input, not considering that the mass burning rate is determined by the fuel’s physical properties and heat input vaporizing the fuel. In this study, a model of LNG pool fire controlled by material physical properties was developed using fire dynamics simulator (FDS), and was validated against LNG pool fire experiments carried out by Mary Kay O’Connor Process Safety Center (MKOPSC). Statistical performance measurement shows that the model is superior to the semi-empirical approaches in predicting the mass burning rate of LNG pool fire under different pool sizes. A flame geometry analysis software was developed comparing different algorithms, and the centroid method was selected. The results show that the fire model (200 kW/m3 as flame contour) can accurately predict the flame geometry observed in the experimental runs. The influence of wind velocity and dike height on the mass burning rate was also investigated. The results show that the height of the concrete dike is negatively correlated with the mass burning rate of LNG pool fire. The effect of wind velocity on LNG mass burning rate is twofold. The forced convective boundary layer at lower wind velocity promotes LNG combustion and increases the mass burning rate, while higher wind velocities reduce the mass burning rate due to the reduction of the thermal radiation feedback. The findings in this study will contribute to an accurate risk assessment of LNG pool fire accidents in the process industry.

Gas permeameter for polymers and nanocomposites: a new equipment

Information on the gas transport coefficients in the permeation of homogeneous semipermeable materials such as semicrystalline polymers under extreme pressures and temperatures is rarely found in the literature. Therefore, the objective of this work is to showcase innovation regarding the accuracy and usability of the medium pressure and temperature gas permeameter suitable for polymeric and polymeric nanocomposite plates built by the authors, which was tested with nitrogen at 1 MPa and 69 °C (342.15 K) permeating pure high density polyethylene samples (HDPE) and HDPE samples with added nanoclay, redoing the tests published in a previous work on the subject. The results were compared against data obtained previously and information present in the literature, validating the permeameter presented in this work, which is capable of analyzing gas permeability under the described conditions with greater accuracy and ease of operation than the previous model for the values of the transport coefficients of nitrogen permeating HDPE, demonstrating that the implemented improvements and advances were adequate, allowing the measurement of the transport properties of gases permeating polymeric and nanocomposite plates, necessary information for the design of risers for the transportation of oil and natural gas, for example.

ROLE OF METHANE IN CLIMATE CHANGE AND OPTIONS FOR MITIGATION-A BRIEF REVIEW

CH4 is a powerful greenhouse gas. It is present in the atmosphere in very low concentrations. Nevertheless, it is the third most important greenhouse gas after water vapour and carbon dioxide (CO2). Water vapour is present in variable amounts. CO2 contributes about 50% to the enhanced greenhouse effect, CH4 about 15-20% and nitrous oxide (N2O) about 6%. Methane (CH4) is a hydrocarbon and the primary component of natural gas. Methane is also a potent and abundant greenhouse gas (GHG), which makes it a significant contributor to climate change, especially in the near term (i.e., 10–15 years). Methane is emitted during the production and transport of coal, natural gas, and oil. Emissions also result from livestock and other agricultural practices and from the decay of organic waste in municipal solid waste landfills and certain wastewater treatment systems. Methane is the second most abundant GHG after carbon dioxide (CO2), accounting for 14 percent of global emissions. Though methane is emitted into the atmosphere in smaller quantities than CO2, its global warming potential (i.e., the ability of the gas to trap heat in the atmosphere) is 25 times greater. As a result, methane emissions currently contribute more than one-third of today’s anthropogenic warming
 In this study an integrated assessment is performed of the contribution of methane to climate change especially from agricultural fields and the options for methane control. The main aim of the study was to analyze future trends in global methane emissions, the associated climate change, and the costs of emission control in terms of agricultural surface methane emissions.

Assessment of Profitability and Impact of Risked Variables on the Viability of Ajaokuta-Kaduna-Kano Gas Pipeline

The Nigeria Gas Master Plan (NGMP) was developed in 2008 as a result of the Country’s resolve to become a major player in the international gas market as well as to lay a solid framework for gas infrastructure development within the domestic market. The full liberalization of the gas industry translates to a clear definition of the roles of the different stakeholders in the industry, viz. government, institutional financiers, investors, and others. In line with the core mandate of infrastructure development and market expansion of the master plan, the pipeline is identified as a major and significant infrastructure for natural gas transportation and distribution. The South-North pipeline, i.e., Ajaokuta-Kaduna-Kano (AKK) pipeline option, requiresa significant upfront investment running into billions of dollars and is also characterised by a long lead time as many years may elapse before revenues begin to accrue. Because of the large upfront expenditure required for this project, it is imperative that investors are well informed of the risk to which their capital is exposed. This research seeks to evaluate using appropriate techniques for the economic justification of AKK. In assessing the economics of the AKK pipeline option, the discounted cash flow analysis (DCF) was employed using the following project profit indices viz; NPV, IRR, and payback. Initial investment cost (IIC) comprises the cost of constructing pipelines and compressor stations. Based on industry practice, operations and maintenance costs were assumed to be 2% of IIC, the debt ratio was 60:40, and pipeline capacity was estimated using the Weymouth formula as provided in the pipeline’s rule of thumb. The cost of equity and debt was accounted for using an average weighted cost of capital. Finally, a probabilistic analysis using “@risk” was run on key inputs to test their sensitivities. AKK was estimated to have an annual gas delivery of 2.3bcm, an investment cost of $2.009 billion, and a discount rate of 15% was used. The pipeline was found to be viable, with an NPV of $484 Million, an IRR of 17.7%, and a payback period of 7 years for forty years of operation. The pipeline cash flow model was sensitive to discount rate, CAPEX, and Pipeline capacity. The Ajaokuta- Kaduna-Kano pipeline has a positive NPV of approximately $484.40 million for forty years of operation. This results in an average of about $12.11 million present value of operating net cash flow per annum, which means that the business cash flow can meet all the operating costs and still return a positive net profit.

Fabrication and Application of 1653.7 nm Methane Sensor

In industries such as coal mining, natural gas transportation and waste-to-energy, methane detection is an essential step. In order to reduce the risk and improve accuracy, laser sensors are used to detect methane. Aiming at the characteristics of the absorption peak of methane gas at 1653.7 nm, the 1653.7 nm distributed feedback laser was obtained from the multi quantum well materials design and ridge-wide pattern design to device packaging by using metal-organic chemical vapor epitaxial deposition, holographic exposure, and nanoimprint lithography. The laser performance achieves a side-mode suppression ratio of 54 dB, a slope efficiency of 0.372 W/A, a threshold current not greater than 12 mA, a saturated optical power greater than 20 mW, and stable optical and electrical properties. Based on this laser, for methane gas with a concentration of 0% to 3%, the loss is stable with the change of gas concentration, and the absorption sensitivity to methane is 0.20237 dB/%.

Hazard Identification of Liquefied Natural Gas (LNG) Transportation and Storage in DKI Jakarta Province

LNG is an alternative fuel to replace diesel and gasoline. The use of LNG as a fuel has many advantages from various aspects. Besides having advantages, LNG also has disadvantages because it contains dangers in it. LNG is a volatile material that is easily flammable, which causes fires and explosions. Environmental Risk Assessment (ERA) is a systematic method used to measure the magnitude of the risk of a process and product that is a hazard to human health and ecology. By conducting an ERA, the risks and hazards of LNG are known. In carrying out the research, describing the LNG delivery system, identifying hazards in the event of LNG released from the carrier, making accident scenarios along with the outcome events that will occur, collecting data, calculating the frequency of accidents and their consequences, determining existing risks, and providing preventive actions, and mitigation. Hazard evaluation was determined using fault tree analysis (FTA) and event tree analysis (ETA). Based on identifying hazards to the storage and transportation of LNG, it is classified into category four and server (severe). Scenarios of releasing LNG into the environment in the process of transporting and storing LNG can be caused by several things, including external factors, failure in filling, and failure due to excess pressure so that it can cause fire pools/BLEVE events, cloud vapor explosions, flash fires, and cloud vapors. Based on the level of risk entered into, not tolerable action at the next opportunity.

A study on the dynamic responses of a steel catenary riser transporting varying-density flow and subjected to regular waves

In order to transport crude oil and natural gas from seabed wells to surface floating platforms, the steel catenary risers have been widely used, which are long, flexible and inclined with geometric and structural nonlinearities. These risers are inevitably subjected to waves and vibrate with time. Meanwhile, they may transport oil and natural gas at the same time, in which the total fluid density may change with time and space. In this paper, a nonlinear dynamic model of a steel catenary riser excited by the internal varying-density flow and the external regular waves is theoretically modelled. The present model is numerically solved and validated with the comparisons to experiments and simulation results. The dynamic responses of the riser are analysed and the results demonstrate that when the fluid density inside the riser is fluctuating with a small circular frequency, the vibrations of the riser will be dominated by the internal varying-density flow, however for a large circular frequency, the vibrations of the riser will be dominated by the external regular waves. The dynamic responses of the riser in the region dominated by the external regular waves will be seldom affected by the internal varying-density flow and vice versa.

Preventing the Formation of Methane Hydrates in Natural Gas Transmission Pipelines–A Comprehensive Review

Hydrates are usually formed during the transportation and treatment of natural gas, resulting in hydrate plugging of pipelines. Hydrates are crystal like structure being formed from the mixture of gas and water. They occur at low temperature and highpressure conditions. These hydrate plugs cost the oil and gas industry significant amounts in revenue cuts and is a major problem for the industry. There are many preventive measures that can be implemented such as inhibitors to avoid the formation of hydrates. This paper aims to highlight the different measures and analyse their effectiveness for hydrate-plug prevention. One such method for the reduction of hydrate formation is the removal of existing hydrates by using different types of inhibitors. The most common method of hydrate prevention in deep-water developments is injection of thermodynamic inhibitors, which include methanol, glycols, and others. If hydrate prevention methods are unsuitable and hydrates are liable to form, the process of dehydration can be used wherein the water gets removed from the gas stream. Electrical heating is also used as a way to dehydrate the pipe. This paper compares a variety of inhibitors and various hydrate preventive methods and discusses their influence in the mitigation of hydrate formation in gas pipelines.

Dependence of flow coefficient on the cone angle and relative opening of natural gas control ball valves

Natural gas control ball valves are fluid control devices that regulate the flow and direction of the medium in a natural gas transportation system, and nowadays the requirements for valve intelligence are increasing. To implement the intelligent control of the valve system, the precise acquisition of the operating parameters of the control ball valve was studied in this paper. A numerical simulation of the internal flow field of a V-shaped ball valve was conducted based on a finite volume method and an renormalization group (RNG) k–ε turbulence model. A valve performance test bench was established, and the pressures at the inlet and outlet of the valve at various relative openings were measured, in which the accuracy of the numerical model was verified. Through numerical simulations, the internal flow characteristics at various relative openings and spool cone angles were studied. By comparing the influence of three different relative openings on the valve internal flow field, it was found that the valve showed better flow characteristics under the relative opening of 80%, and the increase of the cone angle effectively improved the unstable flow in the valve. An accurate expression between the external parameters of the valve operating condition and the internal flow was established, and the expression is the theoretical basis to implement intelligent control. This study provides strong technical support for an efficient operation of natural gas pipelines.

Petroleum Pipeline Interface Recognition and Pose Detection Based on Binocular Stereo Vision

Liquified natural gas (LNG) manipulator arms have been widely used in natural gas transportation. However, the automatic docking technology of LNG manipulator arms has not yet been realized. The first step of automatic docking is to identify and locate the target and estimate its pose. This work proposes a petroleum pipeline interface recognition and pose judgment method based on binocular stereo vision technology for the automatic docking of LNG manipulator arms. The proposed method has three main steps, including target detection, 3D information acquisition, and plane fitting. First, the target petroleum pipeline interface is segmented by using a color mask. Then, color space and Hu moment are used to obtain the pixel coordinates of the contour and center of the target petroleum pipeline interface. The semi-global block matching (SGBM) algorithm is used for stereo matching to obtain the depth information of an image. Finally, a plane fitting and center point estimation method based on a random sample consensus (RANSAC) algorithm is proposed. This work performs a measurement accuracy verification experiment to verify the accuracy of the proposed method. The experimental results show that the distance measurement error is not more than 1% and the angle measurement error is less than one degree. The measurement accuracy of the method meets the requirements of subsequent automatic docking, which proves the feasibility of the proposed method and provides data support for the subsequent automatic docking of manipulator arms.