Carbonate Acidising Calculation Model Coupled with Dual-Fractal Wormhole

2021 ◽  
Author(s):  
Hewen Zhang ◽  
Honglan Zou ◽  
Xuemei Yan ◽  
Mingyue Cui ◽  
Chong Liang ◽  
...  
Keyword(s):  
Production Rate ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Calculation Model ◽  
Acid Strength ◽  
Pumping Rate ◽  
Effective Measure ◽  
Skin Factor ◽  
Fractal Distribution ◽  
Quantitative Calculation

Abstract As recognized as the most economical and effective measure to increase carbonate oil and gas well production, matrix acidising is widely used. The main feature of acidising and the key influence factor of increasing production is what kind of acid etched wormholes can be formed. The actual etched wormholes grow in disorder and randomly, that's why it is extremely difficult to describe by classical mathematical methods. Due to the lack of a quantitative calculation model for the growth law of acid-etched wormholes, penetration depth, competition and distribution patterns among different etched wormholes, an effective method for acidising parameters optimization cannot be formed. The stimulated production of different wells vary greatly. In order to establish the corresponding quantitative calculation model for geometric size of acid etched wormholes, three-dimensional competitive distribution of different wormholes, and production prediction, also to achieve the quantitative optimization of treatment parameters for different wells and improve oil and gas production, firstly, we designed and completed indoor core etched experiments and CT scanning technology to obtain the true three-dimensional morphology of linear acid etched wormholes. Besides, the radial wormholes in 14 cubic feet of super large cores were proven to meet the requirement of fractal. The fractal dimensions of these two wormhole types were also obtained. Furthermore, a quantitative calculation model for the wormhole length expansion was established. Secondly, according to the mathematical model of extending competition among different acid etched wormholes, the fractal distribution law of the length of wormholes in the vertical direction is obtained. Combined with the fractal wormhole length calculation model, a method to solve the dual fractal model by calculating the maximum wormhole length is given. Finally, the classic acidised production rate calculation model was revised. The influence of the three-dimensional expansion length and distribution of wormholes on the skin factor was considered in detail. The sensitivity of key acidising parameters, such as acid strength and pumping rate, was also analyzed. The results show that both the linear wormholes obtained from conventional cores and the radial wormholes obtained from super-large cores can be described by fractal geometry. The fractal dimension corresponding to the optimal pumping rate is 1.46-1.63. Considering the dual-fractal distribution of acid-etched wormholes, the skin factor is larger than that of the conventional equalization model. This is mainly due to the fact that the equalization model only uses the maximum length of the wormholes. This also explains why wells or layers with negative skin factors can still increase production rate after uniform acidising. At the same time, for a specific layer, there is a better acid strength and pumping rate. With these parameters, the acid consumption and predicted production rate are better, which provides a theoretical basis for the quantitative optimization of acidising treatment parameters.

The Hydrodynamic Response and Frequency Domain Analysis of Deep Sea Truss Spar Platform

2013 ◽  
Vol 734-737 ◽  
pp. 1308-1312
Author(s):  
Song Sang ◽  
Xiao Shi ◽  
Chang Dong Li
Keyword(s):  
Frequency Domain ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Frequency Domain Analysis ◽  
Water Area ◽  
Calculation Model ◽  
Gas Production ◽  
Floating Body ◽  
Spar Platform ◽  
Oil And Gas Production

With the development of marine oil going to the deeper water area, SPAR platform with its many advantages has gradually become the mainstream of the offshore oil and gas production facilities. In this paper, the Spar platform three-dimensional hydrodynamic model establish is established firstly, then the floating body hydrodynamic is calculated by using the three-dimensional flow theory to get Spar platforms transfer function and hydrodynamic parameters of its motion response. At last, the frequency domain for floating body and mooring system coupling calculation model is analyzed.

scholarly journals Investigations of polyethylene of raised temperature resistance service performance using autoclave test under sour medium conditions

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 346-354
Author(s):  
Guoquan Qi ◽  
Hongxia Yan ◽  
Dongtao Qi ◽  
Houbu Li ◽  
Lushi Kong ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Service Performance ◽  
Degree Of Branching ◽  
Temperature Resistance ◽  
Temperature Conditions ◽  
Dimensional Network ◽  
Gas Medium ◽  
Better Than

Abstract The chapter deals with the performance evaluation of the polyethylene of raised temperature resistance (PE-RT) and polyethylene (PE) using autoclave test under sour oil and gas medium conditions. The analyses of performance changes showed that PE-RT has good media resistance at 60°C. As the temperature increases, its mechanical properties decrease, accompanied by an increase in weight. Comparative analyses showed that no matter what temperature conditions are, PE-RT media resistance is better than PE80. The better media resistance of PE-RT depends on its higher degree of branching. Short branches are distributed between the crystals to form a connection between the crystals, thereby improving its heat resistance and stress under high-temperature conditions. PE-RT forms an excellent three-dimensional network structure through copolymerization, ensuring that it has better media resistance than PE80. However, the mechanical performance will be attenuated due to the high service temperature.

Study of dynamic pressure on the packer for deep-water perforation

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 215-223
Author(s):  
Hao Huang ◽  
Qiao Deng ◽  
Hui Zhang
Keyword(s):  
Deep Water ◽  
Peak Pressure ◽  
Orthogonal Design ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Calculation Model ◽  
Well Testing ◽  
Technical Problems ◽  
Wellbore Pressure ◽  
Three Dimensional Finite Element

Abstract The packer is one of the most important tools in deep-water perforation combined well testing, and its safety directly determines the success of perforation test operations. The study of dynamic perforating pressure on the packer is one of the key technical problems in the production of deep-water wells. However, there are few studies on the safety of packers with shock loads. In this article, the three-dimensional finite element models of downhole perforation have been established, and a series of numerical simulations are carried out by using orthogonal design. The relationship between the perforating peak pressure on the packer with the factors such as perforating charge quantity, wellbore pressure, perforating explosion volume, formation pressure, and elastic modulus is established. Meanwhile, the database is established based on the results of numerical simulation, and the calculation model of peak pressure on the packer during perforating is obtained by considering the reflection and transmission of shock waves on the packer. The results of this study have been applied in the field case of deep-water well, and the safety optimization program for deep-water downhole perforation safety has been put forward. This study provides important theoretical guidance for the safety of the packer during deep-water perforating.

Simulation on Torpedo Unsteady Hydrodynamic with the Movement in the Longitudinal Plane

2013 ◽  
Vol 791-793 ◽  
pp. 1073-1076
Author(s):  
Ming Yang ◽  
Shi Ping Zhao ◽  
Han Ping Wang ◽  
Lin Peng Wang ◽  
Shao Zhu Wang
Keyword(s):  
Three Dimensional ◽  
Engineering Application ◽  
Calculation Model ◽  
Trajectory Design ◽  
Design Calculation ◽  
Variable Speed ◽  
Accurate Calculation ◽  
Longitudinal Plane ◽  
Submerged Body ◽  
Mesh Method

The unsteady hydrodynamic accurate calculation is the premise of submerged body trajectory design and maneuverability design. Calculation model of submerged body unsteady hydrodynamic with the movement in the longitudinal plane was established, which based on unsteady three-dimensional incompressible fluid dynamics theory. Variable speed translational and variable angular velocity of the pitching motion in the longitudinal plane of submerged body was achieved by dynamic mesh method. The unsteady hydrodynamic could be obtained by model under the premise of good quality grid by the results. Modeling methods can learn from other similar problems, which has engineering application value.

Finite Element Study of the Cutting Mechanics of the Three Dimensional Rock Turning Process

2015 ◽  
Author(s):  
Demeng Che ◽  
Jacob Smith ◽  
Kornel F. Ehmann
Keyword(s):  
Finite Element ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Polycrystalline Diamond ◽  
Close Correlation ◽  
Experimental Results ◽  
Failure Behavior ◽  
Fe Model ◽  
Gas Drilling ◽  
Cutting Mechanics

The unceasing improvements of polycrystalline diamond compact (PDC) cutters have pushed the limits of tool life and cutting efficiency in the oil and gas drilling industry. However, the still limited understanding of the cutting mechanics involved in rock cutting/drilling processes leads to unsatisfactory performance in the drilling of hard/abrasive rock formations. The Finite Element Method (FEM) holds the promise to advance the in-depth understanding of the interactions between rock and cutters. This paper presents a finite element (FE) model of three-dimensional face turning of rock representing one of the most frequent testing methods in the PDC cutter industry. The pressure-dependent Drucker-Prager plastic model with a plastic damage law was utilized to describe the elastic-plastic failure behavior of rock. A newly developed face turning testbed was introduced and utilized to provide experimental results for the calibration and validation of the formulated FE model. Force responses were compared between simulations and experiments. The relationship between process parameters and force responses and the mechanics of the process were discussed and a close correlation between numerical and experimental results was shown.

scholarly journals Corporate Practices of Green Human Resources Management

2021 ◽  
Vol 15 (1) ◽  
pp. 97-105
Author(s):  
Ardeshir Bazrkar ◽  
◽  
Ali Moshiripour ◽  
Keyword(s):  
Human Resources ◽  
Environmental Performance ◽  
Management Practices ◽  
Oil And Gas ◽  
Human Resources Management ◽  
Environmental Knowledge ◽  
Effective Measure ◽  
Resources Management ◽  
Green Education ◽  
Education And Development

Green education and development has a great impact upon improving the environmental performance of companies. Using the example of Iranian small and medium-sized oil and gas enterprises, the article evaluates the practices’ effect on environmental performance. The survey covered 386 employees from 30 companies. The most common measures of green human resources management were analyzed. All these practices have a positive and significant effect on the environmental performance of companies. The action of green education and development was introduced as the most effective measure. The results also demonstrated that four practices of green human resources management have a positive and significant impact upon performance due to environmental knowledge. Companies can use the findings of this research in implementing the green human resources management practices and continuous improvement of the environmental performance.

Numerical Simulation on Mooring Performance of LNG-FPSO System in Realistic Seas

2005 ◽  
Author(s):  
Yoshiyuki Inoue ◽  
Md. Kamruzzaman
Keyword(s):  
Time Domain ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Time Domain Analysis ◽  
Analysis Tool ◽  
Motion Response ◽  
Non Linear ◽  
Floating System ◽  
Exciting Forces ◽  
The Time Domain

The LNG-FPSO concept is receiving much attention in recent years, due to its active usage to exploit oil and gas resources. The FPSO offloads LNG to an LNG carrier that is located close to the FPSO, and during this transfer process two large vessels are in close proximity to each other for daylong periods of time. Due to the presence of neighboring vessel, the motion response of both the vessels will be affected significantly. Hydrodynamic interactions related to wave effects may result in unfavorable responses or the risk of collisions in a multi-body floating system. Not only the motion behavior but also the second order drift forces are influenced by the neighboring structures due to interactions of the waves among the structures. A study is made on the time domain analysis to assess the behavior and the operational capability of the FPSO system moored in the sea having an LNG carrier alongside under environmental conditions such as waves, wind and currents. This paper presents an analysis tool to predict the dynamic motion response and non-linear connecting and mooring forces on a parallel-connected LNG-FPSO system due to non-linear exciting forces of wave, wind and current. Simulation for the mooring performance is also investigated. The three-dimensional source-sink technique has been applied to obtain the radiation forces and the transfer function of wave exciting forces on floating multi-bodies. The hydrodynamic interaction effect between the FPSO and the LNG carrier is included to calculate the hydrodynamic forces. For the simulation of a random sea and also for the generation of time depended wind velocity, a fully probabilistic simulation technique has been applied. Wind and current loads are estimated according to OCIMF. The effects of variations in wave, wind and current loads and direction on the slowly varying oscillations of the LNG and FPSO are also investigated in this paper. Finally, some conclusions are drawn based on the numerical results obtained from the present time domain simulations.

Prediction of Sand Production Through Porous Media: Mechanisms and Challenges to Optimising the Inefficiencies

2021 ◽  
Vol 18 (4) ◽  
pp. 45-52
Author(s):  
Wenhua Huang ◽  
Yan Huang ◽  
Juan Ren ◽  
Jinglong Jiang ◽  
Marischa Elveny
Keyword(s):  
Production Rate ◽  
Oil And Gas ◽  
Phenol Formaldehyde ◽  
Fundamental Issue ◽  
Sand Production ◽  
Drag Forces ◽  
Induced Drag ◽  
Porosity And Permeability ◽  
Production Conditions ◽  
Methods Of Control

One of the challenges facing drilling companies in the completion and production of oil and gas wells is sand production from the formation. The ability to predict sand production in the wells of a reservoir, to decide to use different methods of control is considered a fundamental issue. Therefore, analysis and study of sand production conditions and selecting the optimal drilling route before drilling wells are significant issues that are less considered. According to the findings of this study, due to the sand grains adhesion issue, saturation increase has caused to increase in the intermolecular uptake, and therefore moisture has been decreased. It leads to reduction in the sand production rate. Pressure increase has a direct relationship with the sand production rate due to increased induced drag forces. Moreover, phenol–formaldehyde resins provided an acceptable measurement as there are no significant changes in porosity and permeability.

Study on Spatial Mechanical Characteristic of High-Speed Railway Ballastless Slab Track on Subgrade

2012 ◽  
Vol 503-504 ◽  
pp. 1010-1015 ◽  
Author(s):  
Qing Yuan Xu ◽  
Bin Li
Keyword(s):  
Temperature Gradient ◽  
Mechanical Characteristic ◽  
High Speed ◽  
Three Dimensional ◽  
Calculation Model ◽  
Slab Track ◽  
Combined Load ◽  
Railway Line ◽  
Spring Element ◽  
Ballastless Track

By using beam element to model rail, spring element to model fastener, solid element to model different components of ballastless track, contact element to model the connection between each component of ballastless track, a statics three-dimensional nonlinear finite element mechanical model for calculating the forces transmission among rail, fastening and different component of ballastless slab track on subgrade was established. Experimental data of Suining-Chongqing railway line was given to validate the calculation model. Force of ballastless slab track on subgrade under gravity load, train load, uneven settlement load, temperature gradient load as well as combined load was analyzed. Results show that: spatial forces characteristic of ballastless slab track is very notable under train load; uneven settlement load as well as temperature gradient load has significant influence on the mechanical characteristic of ballastless slab track; force of ballastless slab track increases significantly under combined load than that of under any single load.

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