Liquid Loading Research Articles

Dynamic behaviors of cavitation bubbles near biomimetic surfaces: A numerical study

This work is devoted to numerical studies of dynamic behaviors of underwater cavitation bubbles and the associated fluid flow phenomena such as high-speed liquid jet and pressure loads characteristics near biomimetic shark skin surfaces. Potential damages to the surface caused by cavitation bubbles are numerically quantified by the pressure peak, pressure duration and pressure impulse at the surface center. This work utilizes a compressible VOF multiphase model in conjunction with user defined functions (UDFs). The model has been validated against published experimental data in terms of bubble morphological evolution and the time-dependent liquid film thickness. The results reveal that the shark skin-inspired surfaces have important influence on bubble dynamics, water jets and shock wave pressures under various stand-off parameters. Violent deformation and splashing of the bubbles with weak liquid jet impact and pressure impulse can be observed on the surface covered with triangular shaped structures, accompanied by a certain degree of attenuation on the impacting strength and range of the shock waves. Additionally, the migrating and coalescing behaviors of bubble pairs are reduced with the increase of the initial interbubble distance. The large bubble–wall distance can considerably alter the direction of the microjet flow away from the shark skin-inspired surface. These findings shed the light for designing and controlling of multiple cavitation bubbles collapse near biomimetic surfaces of high-speed marine applications.

Hydrate formation and deposition behaviors with kinetic inhibitors under pseudo multiphase flow

With the successful application of kinetic hydrate inhibitors (KHIs) on hydrate plug prevention, there is a growing trend towards the development of affordable and environmentally friendly KHIs for solving challenges of high cost and inadequate biodegradability from their commercial KHIs. Therefore, further evaluation on the inhibitory effect of the developing inhibitors is needed under multiphase flow conditions. In this study, a high-pressure, fully visible rocking cell were used to simulate the multiphase transportation and both commercial KHIs and environmentally friendly KHIs were considered. Under the flow conditions of 60 % liquid loading and 20 % water cut, the results demonstrated that PVCap showed excellent inhibition performance with no hydrate formation at concentrations of 0.5 wt%, 0.2 wt% and 0.1 wt%. Although pectin exhibited certain inhibitory effect on hydrate growth rate and formation quantity, but it demonstrated a strong promoting effect on hydrate nucleation opportunities and rates. However, sodium alginate, which shares similar hydrate inhibition characteristics with pectin, exerted significantly promotional effects in terms of induction time, growth rate, and water conversion. Furthermore, the addition of pectin and sodium alginate led to the formation of hydrate balls in several test runs, resulting in complete pipeline blockage. Another noteworthy discovery was the relationship between the growth rate and final water conversion of hydrates, which exhibited an initial increase followed by a decrease, while the induction time exhibits an inverse trend, as the flow velocity increased.

A Deep Regression Method for Gas Well Liquid Loading Prediction

Summary Liquid loading occurs when gas production falls below the critical liquid-carrying flow rate of the gas well, resulting in the inability to remove the condensate or water in the gas well. Liquid loading can lead to a sharp reduction in production, which affects the gas well ultimate recovery. Accurate prediction of the timing of liquid loading is important for implementing mitigations that reduce liquid accumulation in the production tubing and prevent gas production impairment, as well as for the stability of production. Existing liquid-loading forecasting methods have a time offset in the determination of liquid loading, and there is great variation in the results for different gas wells. Currently, supervisory control and data acquisition (SCADA) systems are widely used for gas well production data acquisition, but the data are not effectively utilized. Deep machine learning techniques are applied to the field data from gas wells and have achieved significant effectiveness. In this study, a bidirectional long short-term memory network (Bi-LSTM) was used to conduct feature extraction on the production data, and the extracted feature was spliced together with the geological and engineering parameter feature. These features were combined with self-attention mechanisms to predict the time of the next liquid loading. Because the modeling results fit the actual liquid loading in production scenarios better, our method also customizes the loss functions. Experimental verification was conducted using actual production data from 13 gas wells. The recall was 1 and F1 was 0.87 for the experimental data in the model, and the customized loss function led to a 6.5% improvement in F1. The experimental results verify that our method can accurately forecast liquid-loading onset in gas wells in a timely manner, which can help reduce costs and increase efficiency in shale gas production.

Improved Two-Fluid Model for Segregated Flow and Integrated Multiphase Flow Modeling for Downhole Pressure Predictions

This work presents an integrated multiphase flow model for downhole pressure predictions with the purpose of producing relatively more accurate predictions under wide-flowing conditions while maintaining a simple form. As a component of the integrated model, an improved two-fluid model for segregated flow is proposed. The new two-fluid model was developed by improving the modeling of the wetted perimeters and the liquid wall shear stress. It outperformed five other existing state-of-the-art models in predicting the liquid holdup and pressure gradient of 11 experimental datasets from the literature, with an average relative error of 37.6% for liquid holdup predictions and 24.0% for pressure gradient predictions. The model succeeds in capturing the effects of inclination angle, pressure or gas density, and liquid and gas superficial velocities on liquid holdup and pressure gradient. The integrated model incorporates the state-of-the-art onset of liquid loading predictive model and classifies the flow into two major categories based on the onset of liquid loading that are modeled by two different approaches, respectively. It outperformed the other multiphase flow models in predicting the downhole pressure of 313 field data points, especially the wells that have both segregated and intermittent (mixed) flows. The errors were reduced to 4.4% for the field cases with mixed flow regions and 5.1% for all the field data points.

Sensitivity measurements for a 250 MHz quartz shear-horizontal surface acoustic wave biosensor under liquid viscous loading

Surface acoustic wave (SAW) devices have been used in biochemical assays due to their high sensitivity. The device sensitivity is a function of changes in the density and viscosity of the liquid. Here, we studied the effect of fluid viscosity using a 250 MHz quartz shear-horizontal (SH)-SAW biosensor by monitoring different concentrations of binary aqueous/glycerol solutions. In this study, the sensitivity of the biosensor was determined by fitting the data to models derived from perturbation theory. Measurements in water were used as the reference. For a 0% to 50% glycerol solution, an 87°–204° separation in the phase shift was observed. The slope of the plot of the phase shift vs (ηρ)0.5 was used to indicate the sensor’s sensitivity. The sensitivity for our 250 MHz quartz SH-SAW sensors was calculated to be 3.7×10−3m2sKg. The corresponding mass sensitivity was determined to be 9.25 × 105m2Kg. The limit of detection was calculated to be 36 picograms (pg), while the limit of quantification or LOQ was calculated to be 109 pg. Traditionally, liquid phase measurements have been challenging for SAW devices because liquids dampen the vibrating sensors severely. This problem has been largely solved using a transverse (shear) wave instead of the more popular longitudinal or Rayleigh waves. Liquid measurements are now possible using transverse waves, also known as shear waves, because transverse waves are only minimally attenuated by liquids. Shear-horizontal SAW sensors (SH-SAW) show great promise as label-free biosensors because of their ability to handle liquid samples. However, the viscosity of the liquid still induces loading effects and can be measured when the liquid is loaded onto the SH-SAW propagating surface (delay line). When the liquid above the delay line is perturbed by physical or chemical changes, such as binding to a receptor, it alters the propagating acoustic wave. The SH-SAW device can measure these changes in liquid properties as a change in the wave’s phase compared to the original wave. The device’s phase shift was recorded as a function of the changes in the density and viscosity of the binary glycerol solution and used to determine the sensitivity in the linear dynamic range of responses.

Effects of Sway and Roll Excitations on Sloshing Loads in a KC-1 Membrane LNG Tank

Abstract This study investigates the effects of sway and roll excitations on sloshing liquid loads in a tank, using Ansys Fluent software. The model considered in the study is a 1:50 scaled membrane-type tank, based on a KC-1 membrane LNG tank designed by Korea Gas Corporation (KOGAS). The volume of fluid (VOF) method is used to track the free surface inside the tank, and the standard k-ε model is applied to express the turbulent flow of the liquid. To explore the motion of the tank under excitation, a user-defined function (UDF) and a dynamic mesh technique are employed to control the external forces exerted on the tank through its motion. The results, in the form of time series data on the sloshing pressures in the tank under pure sway, roll, and coupled sway-roll, are analysed, with specific ranges for the excitation amplitudes and frequencies. We show that variations in excitation frequency and amplitude significantly influence the sloshing loads. Sloshing loads are found to intensify when the excitation frequency matches the tank’s primary natural frequency, 1.0 ω1′. Furthermore, with coupled sway-roll excitations, the sloshing loads are weakened when the sway and roll are in-phase and are intensified when these are out-of-phase. Fast Fourier transform analysis provides insights into the frequency domain, showing that the dominant frequency is 0.88 Hz and it is approximately equal to the tank’s primary natural frequency, 1.0 ω1′.

A responsive viscosity sensing system with a flow channel based on a one-port resonator

Recently, more and more SAW sensors have been developed for viscosity sensing, bringing different ways of contacting the liquid with the device. It is important to choose a contact method that maximizes the performance of the device. Therefore, this paper describes the development of devices for detecting the viscosity of liquids and the evolution of fluid-device contact methods. And a responsive viscosity sensing system with a flow channel for real-time monitoring is developed in our work. The channel, made of polycarbonate, is responsible for regulating the flow direction and ensures that the sensing area covered by the liquid, the mass, and the morphology of the liquid load on the sensor are the same for each detection. Based on a one-port resonator, the sensor offers a faster response time, lower attenuation, and higher sensitivity of 38.6 kHz/ kg m−2 s−0.5. The real-time detection results also show that changes in flow rate do not affect resonant frequency. In addition, the sensor's frequency response to viscosity-density product has been conducted using glycerol solution to get a standard curve. Then the viscosity of the rinse water can be accessible by the frequency response. For the first time, the rinse solution directly from the washing machine is used to measure the residual detergent concentration. The residual concentrations of detergent in the first and second rinse solutions are 23 ppm and 6 ppm, respectively. The system is more convenient, more responsive, and more accurate.

Identification and prediction of hydrate–slug flow to improve safety and efficiency of deepwater hydrocarbon transportation

The vast hydrocarbon resources (oil, gas, and gas hydrate) in deepwater areas are considered one of the most significant resources of the future. However, the dangerous flow patterns and blockage accidents caused by hydrates threaten the safety and efficiency of the transportation process. A mutual interaction exists between hydrate growth and multiphase flow. In this study, hydrate formation and gas–slurry two–phase flow tests were conducted in a pure water system with a constant pressure (4 MPa) and various liquid loadings (40–80%) in a visual flow loop. It was found that the hydrate growth process in the dynamic system included bubble promotion, subcooling promotion, and mass transfer inhibition. Meanwhile, two atypical slug patterns (rapid conversion slug and deposition slug) in the vertical upward flow were determined, which corresponded to the promotion and inhibition regions. In the rapid conversion slug flow, the churn segments replaced the original Taylor bubbles when the liquid loading was less than 60%. In the deposition slug flow, slurry shedding phenomena was observed. In addition, the hydrate particle deposition behavior was found to inhibit hydrate growth and cause flow pattern shifts, but did not trigger the differential pressure surge. The gas isolation caused by the liquid plug and energy dissipation due to the collision between hydrate particles and the tube wall may be responsible for the sudden increase in pressure drop. Furthermore, the feasibility of predicting hydrate blockage using the differential pressure method was explored. The experiment results showed that this warning method was effective when the liquid loading was below 76%. And an effective warning can improve the transport capacity by approximately 34%.

Study on improving liquid carrying performance of annular jet pump gas well with static mixer

AbstractIn the process of natural gas extraction, the phenomenon of liquid loading will affect the efficiency of gas well extraction and reduce the life of the well. Compared with conventional drainage gas extraction technology, the jet pump can not only reduce the bottom back pressure and ensure the stable production of gas reservoirs but also promote the final recovery rate. Since the jet pump relies on the interaction between fluid particles to transfer energy, the energy loss is large and the efficiency is low. To maximize the advantages of the gas‐driven jet pump, this study innovatively combines a static mixer with an annular jet pump. Utilizing the cyclonic effect produced by the static mixer, the original gas‐liquid axial motion is transformed into a stronger vortex motion, and the liquid droplets are changed into a liquid film that is easier to carry, which significantly improves the discharge efficiency of the jet pump. This study uses a combination of numerical simulation and experimental analysis to compare the associated effects of the new annular jet pump (NAJP) and the conventional annular jet pump (CAJP) on the liquid‐carrying performance of gas wells in terms of cyclonic effect, droplet breakage ratio, and pump efficiency. The results show that, compared with CAJP, NAJP increases the mass flow rate of the sucked fluid. The droplet breakage ratio increases by 15.4% year‐on‐year, while the critical liquid‐carrying flow rate is reduced by about 10.7%, resulting in a maximum pumping efficiency of 37%, an increase of about 30.7% year‐on‐year. At the same time, the reduction of the energy coefficient means lower energy consumption. In summary, NAJP is better than CAJP in terms of liquid‐carrying effect and efficiency.

A modified comprehensive prediction model for wellbore temperature-pressure field and liquid loading of gas wells

Wellbore liquid loading is a severe problem in the late stage of natural gas production, and precise prediction of liquid loading is helpful for taking dewatering measures timely to avoid the related hazards. Based on the flow and heat transfer mechanisms of gas-liquid two-phase annular flow in wellbore, a new model for calculating temperature and pressure field of the gas well considering the effects of the velocity difference between the gas core and liquid film and the migration of liquid droplets was established first, which laid a foundation for the prediction of liquid loading in the whole wellbore. Then, based on the flow mechanism of liquid film, a liquid loading prediction model for the whole wellbore of gas well was established, with the zero shear force between tubing wall and liquid film under low liquid holdup and the critical liquid holdup of liquid film bridging and plugging gas core taken as criteria for judging liquid loading, and the coupling solution method for the above model was worked out. Production data pairs of gas wells were used to verify the reliability of the model. The results show that our model can accurately calculate the wellbore temperature and pressure of liquid-producing gas wells. The temperatures predicted by the model have a maximum relative error of 11. 86% and an average relative error of 5. 96%, while the pressures predicted have a relative error range from 0. 09% to 8. 42%. In terms of prediction accuracy and prediction error of gas well liquid loading state, the modified model has much more precise prediction results of liquid loading than three classical liquid loading models. Finally, the sensitivity analysis of liquid loading was carried out with an example. The research results can provide theoretical support for the early prediction of liquid loading and dewatering process in liquid-producing gas wells.

Fracture behavior of high-temperature granite subjected to liquid nitrogen cooling: Semi-circular bending test and crack evolution analysis

Liquid nitrogen fracturing is an effective technique for stimulating reservoirs in hot dry rock exploitation. The application of low-temperature liquid nitrogen to high-temperature granite generates thermal stress, thereby altering its mechanical properties and fracture behavior. This study focused on type I fracture characteristics by conducting semi-circular bending tests on high-temperature granite treated with liquid nitrogen. The fracture behavior was analyzed using acoustic emission (AE) and digital image correlation methods. The fractured surface morphology was examined using laser scanning, and fractal theory and tortuosity analysis were employed to assess the fracture surface roughness. Scanning electron microscopy (SEM) provided insight into the impact of liquid nitrogen cooling on fracture characteristics. The findings indicated that treated granite specimens below 150℃ exhibited an increased peak load, fracture toughness, and fracture energy compared to untreated specimens. SEM images revealed isolated microcracks in specimens at 25℃ and 150℃, which effectively passivated pre-existing notches and increased fracture toughness. For granites above 200℃ following liquid nitrogen treatment, P-wave velocity, peak load, fracture toughness, and fracture energy decreased significantly as temperature increased. AE signals were observed earlier for granites at higher temperatures. The length of the fracture process zone increased with temperature, and the crack tip opening displacement exhibited a step-like increase at 600℃ under loading. The fractal dimension of the fracture surface varied with temperature, whereas the tortuosity exhibited a substantial increase with increasing temperature. As the temperature difference increased, an increasing number of microcracks appeared, forming interconnected networks that compromised the rock integrity, ultimately leading to reduced fracture toughness and the development of a rougher failure surface.

True bridging liquid-solid ratio (TBSR): Redefining a critical process parameter in spherical agglomeration

Spherical agglomeration of crystals via addition of an immiscible bridging liquid can improve active pharmaceutical ingredient handling and tabletability. Bridging liquid amount is quantified by the bridging liquid-solid ratio (BSR). However, the optimal range of the BSR for agglomerates to form is highly dependent on the bridging liquid/solvent/antisolvent system. Here, a new definition is introduced to account for bridging liquid-solvent miscibility; true bridging liquid-solid ratio (TBSR). A method for calculating TBSR from the system ternary phase diagram is demonstrated for five different common binder liquids with acetone/water as the solvent/antisolvent system. Results show the value of BSR varies dramatically for a given TBSR as a function of both the system and the solids loading. Experimental salicylic acid agglomeration studies confirm optimal BSR varied widely with binder liquid and solids loading between 0.2 and 2, but the optimum TBSR for all experiments was in a narrow range between 0.05 and 0.15. Thus, TBSR is a robust dimensionless parameter for design and scale up of spherical agglomeration processes.

Modeling of water film generation in up-inclined low liquid loading natural gas pipeline elbows and its implication on internal corrosion occurrence

Condensed water often accompanies natural gas in the transmission process. The water forms thin film when parameters such as temperature and pressure change. This accelerates pipeline corrosion and makes the pipeline wall become thinner. Severe corrosion can lead to pipeline rupture, endangering the pipeline safety and leading to economic losses. The distribution of a water film plays a significant role in the corrosion process, So the work of predicting the distribution of a water film and flow characteristics becomes a key priority when analyzing corrosion in a pipe elbow. In this study, Eulerian, RNG (re-normalization group) k-ε and Eulerian wall film models are employed to establish a pipe elbow model that predicts the locations of water phase accumulation. Combining with a limiting diffusion current density, this model can be used to predict the potential corrosion locations and extent. The proposed model is validated by using velocity and water film distributions and it shows substantial agreement with previous models and results in the literature. From the simulation outcomes, a water film is mainly distributed at bottom while the thickness of the water film increases significantly at the pipe elbow. At the elbow bottom the inlet gas velocity increases, this shifts the high corrosion rate zone from elbow rear to front. Corrosion at the elbow front is more serious regardless of the changes in the inlet liquid velocity, elbow angle or water holdup. Meanwhile, when the gas velocity or elbow angle is large, the water film gradually spreads from the elbow bottom to the side and top parts which are in a high corrosion rate zone and more dangerous. Therefore, weak positions where pipeline elbow corrosion failures may occur can be quickly and conveniently computed and determined by the proposed model.

Analysis of hydraulic performance in a structured packing column for air/water system: RSM and ANN modeling

The study investigated the hydraulic characteristics of a structured packing column for an air/water system using two modeling approaches: artificial neural network (ANN) and response surface methodology (RSM). Seven parameters were identified as influential factors for pressure drop and liquid hold-up. Two correlations for the responses were proposed using the two-factor interaction (2FI) model based on the RSM-central composite design approach. In the ANN modeling, two algorithms were applied: multi-layer perceptron (MLP) and radial basis function (RBF). The optimal MLP structure using the Bayesian Regularization (trainbr) algorithm had two hidden layers, 16 and 8 neurons, and the optimal RBF structure had 42 neurons. The best MSE performance of the MLP network was 0.0938 and 0.0083 for pressure drop and hold-up, respectively, at 16 epochs. The best MSE performance of the RBF network was 0.0685 and 0.0140 for pressure drop and hold-up, respectively, at 42 epochs. Both the ANN and RSM models provided reliable predictions of the experimental data. In addition, ANN's prediction performance (R2 = 0.993) was somewhat better than RSM's (R2 = 0.926). The results showed that gas factor and liquid load had the greatest effect on pressure drop and liquid hold-up, respectively.

Excellent condensate and salt‐resistant foam by anionic‐zwitterionic‐cationic Gemini surfactants compounds for gas well deliquification

AbstractThe blockage caused by liquid loading poses a major problem to the aged gas wells. Various categories of foaming surfactants including zwitterionic, anionic and cationic surfactants are often used for foam‐based gas well deliquification. In this study, a foaming formula containing anionic (sodium lauroyl sarcosinate, LSS), cationic Gemini (C16AGB and C12AGB) and zwitterionic (C16APB and C12APB) surfactants was developed. This foaming formula was first optimized through the foaming ability and foam stability tests, and then evaluated through liquid unloading performance tests under various salinity, condensate, methanol and temperature conditions. Synergy was observed in the foaming ability and foam stability measurements when LSS, C16AGB, C12AGB, C16APB and C12APB were combined at a molar ratio of 5:4:1:4:1. The foaming formula exhibited excellent liquid unloading performance at high salinity (up to 26 × 104 mg/L), high condensate fraction (up to 25%) and high methanol fraction (up to 50%) conditions. The presence of 10% methanol significantly enhanced foaming efficiency (referred to as the ratio of the foam mass to the initial liquid mass) and liquid unloading efficiency of the foaming formula at 20–90°C. Furthermore, the surface tension measurements and the foam morphological investigation were carried out to reveal the observed synergy.

Influencing Factors of Drainage and Production and Quantitative Evaluation in Shale Gas Reservoirs

As a transitional energy source, natural gas plays a crucial role in the energy transition. In the efficient development of shale gas, the drainage and production process, as an important link between hydraulic fracturing and production, determines the recovery rate of individual wells. To clarify the main controlling factors of shale gas drainage and production, provide strategies for classification, and improve the recovery rates of individual wells, a numerical simulation method was proposed to analyze the factors affecting drainage and production, and the VIKOR method was used for quantitative evaluation of the drainage and production effects. The research results showed that: (1) The study identified nine main controlling factors affecting drainage and production performance, including gas saturation, permeability, stress difference, burial depth, formation pressure, cumulative fracture volume, final fracture loss rate, average final diversion ability, and wellbore liquid loading. (2) A workflow for quantitatively evaluating the drainage and production effectiveness of shallow shale gas wells and selecting wells with potential for optimized drainage and production was proposed. The correlation between the evaluation results and EUR fitting had an R2 value of 0.71, indicating a good level of credibility. (3) The evaluation results for the target gas field indicated that out of the 16 representative wells, 12 wells have optimization potential, with 5 wells showing significant optimization potential. Studying the rules of shale gas drainage and production and evaluating the drainage and production effects can help us to propose refined drainage and production strategies, which are essential for improving the estimated ultimate recovery (EUR).

Development of a novel microplate for high-throughput screening and optimization of DHA producing strains based on CFD technology.

Microtiter plates are suitable for screening and process development of most microorganisms. They are currently the container of choice for high-throughput and small-scale microbial culture, but require optimization for specific work. In this research, a novel type of microtiter plate was developed using computational fluid dynamics (CFD) technology. The new plate provided high oxygen supply and optimal mixing effects for the fermentation culture of docosahexaenoic acid (DHA) producing strains, surpassing the conventional method of strain screening with shake flasks, which was insufficient. The shape of the microtiter plate was modified, and baffles were introduced to improve mass transfer and oxygen supply effects in the vibrating bioreactor. CFD technology was used to model the new plate's characteristics, establishing the superiority of hexagonal microtiter plates with six baffles. Parameters in the incubation process, such as vibration frequency and liquid load, were optimized, and the final result achieved an oxygen transfer coefficient (KL a) of 0.61s-1 and a volume power input of 2364 wm-3 , which was four to five times better than the original 96-well plate. The culture results optimized by the model were also verified. Therefore, this new microtiter plate provides a powerful tool for future high-throughput screening of strains.

Life-cycle deliquification techniques and their application for deep shale gas reservoirs

Deep shale gas resources in the Sichuan Basin have great potential, and this is a major area for future shale gas exploration and development. Deep shale gas wells face problems with liquid loading throughout the production cycle. Regarding deliquification techniques, it is necessary to consider the requirements of gas wells over the full life cycle, as well as the main form of artificial lift used at different stages, to achieve economically efficient development. This paper divides the life cycle of a deep shale gas well into two stages: early production and middle/late production. Pressure-control production is conducted in the early stage of production, whereas investigations on critical liquid-carrying models, the flow distribution in the wellbore, and the main form of artificial lift are conducted in the middle and late stages of production. A recommended scheme of deliquification techniques over the full life cycle has been developed to guide the development and enhancement of artificial lift methods in deep shale gas reservoirs. As of March 2022, in the PetroChina Southwest Oil & Gasfield Company managed-pressure production has been implemented in 14 wells in the early stage of deep shale gas production. In eight wells, plunger gas lift has been implemented in the middle and late stages of production. In seven wells, foam lift has been implemented. The abovementioned techniques are effective in increasing and stabilizing production and achieving deliquification in deep shale gas reservoirs.

Velocity String Revives Production of Deep Gas Wells With Halite Deposition

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 213501, “Reviving Production From Over 100 Deep Gas Wells Suffering From Halite Deposition in Oman Through Velocity String,” by Ahmed Al Rashdi, Babak Ghaempanah, and Amira Al Hijri, PDO, et al. The paper has not been peer reviewed. _ The complete paper describes a scenario in which, following the reduction of system pressure through depletion compression, more than 150 deep gas wells began experiencing halite deposition. Many of the wells with this issue were also suffering from liquid loading. Velocity strings (VS) were installed as the primary means of gas‑well deliquefication. Many of these wells with VS showed no further halite deposition. Consequently, frequent freshwater bullheading (FWB) or cleanout with coiled tubing (CT) were no longer needed. This observation triggered the idea of creating synergy between gas‑well deliquefication and halite management through installation of VS.

Analisis Manajemen Risiko pada Tingkat Kinerja Pelayanan Kapal di PT X

Loading and unloading activities are the transfer of cargo from ship to port or vice versa. One of the loading and unloading activities is on liquid bulk cargo. Loading and unloading activities are related to ship services, namely ET indicators: BT. One of the indicators is Idle Time (IT). Idle Time (IT) is the number of unused working hours during loading and unloading work time at the mooring. IT value < RKAP indicates minimal obstacles to loading and unloading operations. The purpose of this study is to analyze Idle Time in liquid bulk loading and unloading activities every month and analyze the factors that can affect the performance of liquid bulk loading and unloading in 2021 at Company X. This research uses descriptive quantitative methods. The results of the analysis of Company X, namely Idle Time (IT) are not good because IT> RKAP. There are obstacles in loading and unloading activities due to various factors. The inhibiting factors are tool factors, environmental factors and worker factors. This requires good risk management.