The erosion characteristics of high sand flow fields are essential to the durability and performance double jet pumps in oil gas production. Using solid–liquid two-phase theory an model, this study evaluated how particle size, mass rate, power fluid rate affect pumps. findings reveal that mainly occurs on inner wall at throat inlet, outlet, diffuser inlet. With increase from 11 15 L/s, maximum throat's inlet cone escalates by a factor 14.2. inlet's service life is estimated 275 hours. These...

This study aims to solve the problem of recovery efficiency natural gas hydrate being affected by a large amount mud and sand in solid fluidization mining hydrate. Therefore, new method for separation situ sediment spiral-swirling downhole is proposed, corresponding numerical simulation model established realize analysis verification key flow field parameters such as velocity, pressure, sediment, phase distribution. The results show that velocity mixed slurry presents an ‘M’-shaped...

The superlight duplex Mg–Li alloy LZ91 was successfully friction stir lap welded (FSLW) using a high rotational speed of 2000 rpm and the welding 800 mm/min with traditional H13 tool. tensile-shear load joint about 2.01 kN width 12 mm, microhardness nugget zone (about 52 HV) significantly higher than that base material 47.8 HV). fracture occurred along interface distortion zone, showing characteristic shear fracture, indicating this is weak location joint. In addition, it found β phase...

In natural gas hydrate exploitation, the large amount of sand production directly or indirectly leads to low efficiency exploitation and even termination exploitation. A spiral-cyclone coupling separator was used achieve separation mud sand. this study, based on actual size for hydrate, an experimental prototype suitable indoor experiments processed, system built. pressure loss experiment device carried out, results proved correctness numerical simulation model spiral-swirl calculation...

Underground gas storage reservoirs are vital to China's energy infrastructure, facilitating natural peak shaving and supply security. However, cyclic alternating loads from significant pressure fluctuations during injection production operations lead severe erosion wear of tubing strings, complicating safe operation. This study developed a custom jet flow gas–solid–liquid experimental apparatus analyze the effects impact angle, velocity, particle size on rates. An model was established data....

Equipment failure risk identification and assessment are essential part of offshore platform equipment integrity management. Realizing the quantitative modes will help to formulate more reasonable management measures. However, previous methods not enough support precise equipment. Therefore, this paper proposes a new method based on fuzzy set theory, gray correlation analysis Borda method. This creatively proposed approach, which integrates solid expressive ability theory vagueness...

The high hazard mechanical system (HHMS) has three characteristics in the petroleum and petrochemical industry (PPI): risk, cost, technology requirements. For a HHMS, part, component, subsystem failures will result varying degrees various types of risk consequences, including unexpected downtime, production losses, economic costs, safety accidents, environmental pollution. Thus, obtaining quantitative level distribution HHMS to control major accidents ensure safe is vital importance....

Abstract Jet breaking using a high‐pressure nozzle is one solution for natural gas hydrate (NGH) formations, creating larger volume and fluidizing broken solid fragments. Based on the analysis of various jet mechanisms variation flow velocity internal outlet sections different nozzles, straight‐swirling mixed (SSMN) was designed. We obtained effects single nozzle, including influences working pressure target distance hole shape, as well parameters parameters. In addition, we analyzed number,...

In this study, we address a coupled task allocation and path planning problem for multi-unmanned aerial vehicle (UAV) reconnaissance/attack. Both are addressed. We propose algorithm maximizing system utility simultaneous arrival. Moreover, consider the targets resource requirement UAVs constraints based on contract net protocol allocation. Benefits of destroying target costs UAV attacking considered in objective function. To multi-UAV problem, combination cooperative particle swarm...

Abstract In order to reduce operating cost of deep‐sea natural gas hydrate (NGH) solid‐state fluidization mining (SSFM), a device for controlling opening and closing jet nozzles is required. It required meet the specifications work process not affected by changes in water depth well depth. Therefore, design scheme pressure‐controlled sliding sleeve (PCSS) based on principle throttling pressure drop proposed. The controlled flow rate control environmental pressure. Using computational fluid...

The coupled task allocation and path planning problem for heterogeneous multiple unmanned aerial vehicles performing a search attack mission involving obstacles no-fly zones are addressed. importance of the target is measured using time-dependent value. A algorithm proposed to obtain maximum system utility. In utility function, reward target, lengths vehicles, number perform simultaneous considered. length based on Pythagorean hodograph curve calculated, it serves as input problem. resource...

This paper pays close attention to the adaptive neural network tracking control. Aiming at a class of uncertain nonlinear systems with completely unknown output disturbance and time delay, corresponding robust control method is proposed based on backstepping design technology. Neural approximation introduced as very effective estimation technique for modeling partitions in process virtual controller. The suitable Lyapunov–Krasovskii function constructed, by using organic combination Young's...

In drilling and completion operations, a packer is downhole tool to seal the annular space between various sizes of string borehole. As key component packer, slip plays role fixed support in process setting, thus ensuring long-term stable sealing packer. Aiming at problem damage caused by casing pressure on after based stress analysis during material with hardness lower than was selected, its finite element model established. Then, pressure-bearing law teeth under three tooth parameters...