Hang Zhang

• PhD
• China University of Petroleum, Beijing, China

As an important mode of oil and gas transportation, pipelines will produce different forms of defects with the increase of service life and the change of external environment. Regular inspection in pipeline is an important way to ensure the safe operation of pipeline. As an important driving component of the pipeline inner inspection tool, the redu...

As an essential means of energy transportation, pipelines have been widely used in various fields. However, many external factors such as vibration and corrosion can cause damage at the flange part, which seriously affects the safety of pipeline transportation. Quite a number of methods for troubleshooting at pipeline flanges have been continuously...

Timeously detecting pipeline small leakages caused by corrosion, aging, and crack can critically impact structural safety. However, identifying small leaks is challenging and small leaks can gradually develop into significant leakage problems. Although the negative wave method is currently the most common approach used for pipeline leakage detectio...

A method for crack detection on the surface of pipelines that uses residual magnetic detection technology based on the hysteresis effect after magnetizing the pipeline to magnetic saturation has been developed in this study. Support vector regression (SVR) was employed for quantitative assessment. This paper reviewed the magnetization process of th...

Failure Modes and Effects Analysis (FMEA) is an engineering technique widely used to identify, evaluate, and eliminate known or potential failures, problems, and errors and inform risk management decisions. Traditional FMEA uses the risk priority number (RPN) to identify potential failure modes and their levels. However, it displays shortcomings in...

The integrated water distributor (IWD) is the adjustment terminal during the interval injection process. Its quality and performance are directly related to the effect of layered water injection. The IWD’s flow field is considered the research object, and the transient simulation is developed with Fluent dynamic grid and Fluid-Structure Interaction...

The mechanical state of the process zone at the crack-tip is one of the main factors that affect crack initiation and growth in the long-term safe operation of oil and gas pipelines. Many tests showed that the stress and strain fields in the fracture-tip process zone can be used to define the crack propagation behavior. The goal of this paper is to...

Pipeline inner inspection technology based on Pipeline Inspection Gauge (PIG), is the primary means for ensuring the safety of submarine pipelines. The dynamic characteristics of a PIG can change abruptly with the excitation of obstacles such as girth welds inside the pipeline, which would result in failure or inaccuracy of the inspection results....

Pipeline leakage can cause severe hazards and pose significant risks, and leakage detection ensures the operational safety of the pipeline. In this paper, the simultaneous increase in the noise intensity signal of the pipeline wall and the pressure gradient of the flow field in the pipeline were regarded as critical during the leakage detection pro...

The use of Pipeline Inspection Gauges (PIGs) to clean the pipes and understand the exact location of existing pipes is essential to protect them from damage during operation. In-depth study of the most important component sealing disc is a new method to solve the failure of the current PIG in the working process. This study focuses on redesigning t...

As one of the main risks of long-distance oil and gas pipelines, the consequences of pipeline accidents caused by third-party damage (TPD) are usually catastrophic. At present, TPD prevention approaches mainly include manual line patrol, fiber-optical vibration warning, and unmanned aerial vehicle (UAV) line patrol, but there are some limitations s...

Due to geographical restrictions, it is often necessary to lay two pipelines in the same ditch during pipeline construction. However, as developments in natural gas pipelines increasingly incorporate higher grades of steel, larger diameters, and higher pressures, the consequences of an accident caused by leakage, explosion, or ignition become progr...

Free span along a buried gas pipeline is inevitable since the buried gas pipeline is constantly exposed to the complex surrounding environment. A free span is commonly identified by manual inspection, sonar technology, or a remote robot. The main disadvantage of these identification methods is that the detection process is significantly interfered...

Pipeline inspection gauge (PIG), as a kind of pipeline robot, Pipeline inspections gauges (PIGs) have been the main equipment during different stages of operation to perform functions such as pigging and inner inspecting. However, due to the failure of the sealing cup, the PIG is often stuck when it runs in the oil and gas pipeline especially in de...

Regular pigging operation of the pipeline inspection gauges (PIGs) is crucial for pipeline transportation. However, the PIG is often stuck when it runs in the oil and gas pipeline due to the interaction between spherical sealing cup and dent inside the pipe. The stress and strain distribution of the outer edge of the spherical sealing cup can provi...

Free span is a great danger and an unavoidable problem for buried gas pipeline. In this paper, a method for identifying buried gas pipeline free span based on vibration signal analysis under internal excitation load is experimentally studied. Collected signals are pre-processed by sliding average method to reduce noise and smooth the vibration curv...

Water soluble carbon quantum dots (CQDs) were prepared and used as lubricant additives in deionized (DI) water. The impacts of CQDs on the tribological properties of water were evaluated for both Si3N4-on-steel and Si3N4-on-Si3N4 contacts. Experimental results show that the coefficient of friction (COF) reduced in the two types of tribopairs after...

Pipeline is important for gas transportation. Free span of buried pipeline may cause safety problem as a result of decreasing the load-carrying capacity of the pipeline. A method for detecting the free span of buried pipelines based on the inner pipe excitation signal was proposed. Vibration characteristics analysis of the pipe and its surrounding...

Unstable crack propagation velocity following the failure of pipeline steel has always been a problem. In this study, differences between the existing unstable crack propagation calculation models were analysed, and the deficiencies within the crack propagation velocity models were overcome. The hardening coefficient and hardening index of the duct...

PIGs (pipeline inspection gauges) have been the main equipment for pigging, inner inspecting operations in oil and gas pipelines. Due to the insurmountable shortcomings of conventional sealing discs, it is impossible to actively control the PIG when it is running on the pipeline, which leads to no way when the PIG is stuck. In this study, a new typ...

As developments in natural gas pipelines increasingly incorporate higher grades of steel, larger diameters, and higher pressures, the consequences of an accident caused by leakage, explosion, or ignition become progressively more severe. Currently, major technical obstacles include the quantification of the impact of an explosion shock wave of a hi...

Ceramic materials possessing the properties of high-strength and rigidity are widely used in industry. The shell nacre has a layered structure containing both macroscopic and microscopic levels and is equipped with superior qualities regarding hardness and strength. Therefore, the ceramic composites with a nacre-like layered structure have the pote...

During the drilling process, the non-linear contacts between the bit and the bottom hole, the drill string and the borehole wall can cause the bit’s stick-slip vibration, which will shorten the life of the bit and even endanger the safety of the drill string. The severity of stick-slip vibration of a bit can be identified by the rotary speed of a b...

35CrMo steel is a widely used material in machinery equipment for the petroleum industry. With the improvement of exploring technology, some particular complex features cannot be achieved with traditional processing methods. However, electrochemical machining provides a potential solution to such problems, especially in the machining of the turbine...

Black powder is a common contamination problem for natural gas pipeline all over the world. In this study, a method based on the jetting pig is proposed to remove the black powder in natural gas pipeline. Numeric simulations based on the computational fluid dynamics method, were conducted to investigate the dynamic migration process of black powder...

The safety of pipelines is an important factor in the natural gas industry. In natural gas fields, some pipelines are less than 200 mm in diameter, and these pipes cannot be inspected in ordinary inspection facilities. This paper describes the development of a leaf spring caliper to solve this issue. The factors that influence the accuracy of the d...

Pigging is the most effective and common way to remove the wax deposits in pipelines. The discs, cups, or brushes of a pig are executing components for waxy oil deposit removal. In this study, a homemade experiment setup was built and employed to conduct the waxy oil deposit removal experiments with various wax concentration at different scraping s...

Subsea pipeline is crucial for oil and gas transportation. It is advantageous to be able to identify the free-spanning segments of a long subsea pipeline. The existing technologies for detecting the support condition of buried subsea pipelines are constantly affected by complex external environment since they are outer pipeline detecting methods. A...

The behavior of pools of water for lubrication under a point of contact between a glass disk and a steel ball is studied here, employing a home-built apparatus. A deformed water pool is found to form around the contact region under different rolling speeds. To investigate the effect of rolling speed on the water pool, two parameters (advancing angl...

Pipeline inspection gauges (PIGs) are essential for regular maintenance in natural gas exploration in cleaning and inspection. Their sealing discs, made of polyurethane rubber (UR), are often found to be worn quickly due to rubbing against steel surfaces. The damage in the UR sealing disc would cause a PIG stuck in operation (pigging). In this rese...

The continuous collision between a running PIG (pipeline inspection gauge) and girth welds in a pipeline can induce significant vibrations on the PIG, which can harm its mechanical structure. The vibration response caused by the collision between a running PIG and a girth weld was studied both experimentally and theoretically. A two-dimensional dyn...

As a drying method for new construction pipeline, basic bi-directional pipeline inspection gages are employed to dewater the pipeline. Their sealing discs, made of cast grade polyether-based urethanes, are worn out quickly due to the rubbing against steel surfaces under water-lubricated condition. The severe wear out in the polyurethane sealing dis...

Coiled tubing can be used for steel catenary riser pigging operations to remove wax and other debris attached on the interior of steel catenary riser to recover production and ensure safety. Due to its low rigidity, coiled tubing would deform which might finally damage coiled tubing and steel catenary riser. Thus, in order to ensure safety and reli...

Pipeline inspection gauges (PIGs) are needed for operations such as cleaning and internal inspection of the natural gas pipelines to facilitate improvement in efficiency and safety. There is chatter vibrations appeared in PIGs when they run in the dry pipe with the wear of rubber sealing disc. Dry friction-induced self-excited vibration between sea...

Pipeline inspection gauges (PIGs) are needed for operations such as dewatering, cleaning and internal inspection of the oil and gas pipelines to facilitate improvement in efficiency and safety. The friction and dynamic characteristics, as the sealing disc of a PIG passes through the girth weld in a pipe, has been directly studied using a custom-bui...

Inject cable into Coiled Tubing is an important guarantee of the oilfield smart job to supply electrical power and signals down hole to collect and manipulate the real time data. Pumping fluid to inject cable into a reel of CT is a new method for the installation. It is more economic and more adaptable in oil field operation when compared with othe...

Non-stop transmission blockage technologies are the preferred approach used to maximize safety while performing piping maintenance. As an important part of non-stop transmission blockage technologies, the structure of blockage plays an important role in the quality of pipe plugging. Furthermore, it is difficult to plug the pipeline successfully all...

Due to the complex working environment and relatively backward manufacturing technology, an important industrial tool - the air winch - faces a lot of problems, such as wire rope breaking and brake instability. This paper presents a new, mechanical loading, tower-type air winch performance test platform designed to testan air winch after it is manu...