Productivity Optimization and Validation of Multistage Fracturing in a Rare Geomechanical Setting with Production Logging

2021 ◽  
Author(s):  
Gaurav Agrawal ◽  
Ajit Kumar ◽  
Shaktim Dutta ◽  
Apoorva Kumar ◽  
Shashank Pandey ◽  
...  
Keyword(s):  
Flow Condition ◽  
Flow Behavior ◽  
Production Optimization ◽  
Final Decision ◽  
Flow Profile ◽  
Unstable Flow ◽  
Geomechanical Model ◽  
Optimal Flow ◽  
Role Based ◽  
Fracture Gradient

Abstract A reservoir with a rare geomechanical setting of higher stresses at shallower depths and vice versa was fractured. The multistage fracture responses were validated using production logging data. Further, production optimization was achieved by understanding the flow profile and geomechanical setting to decide on an optimal flow condition for the wells. An innovative solution-driven approach was identified with production logging playing a key role. Based on the geomechanical model, calculated fracture gradient indicated higher stress in the shallower section and lower stress in deeper intervals. Multistage fracturing was performed. Post fracturing, production logging was carried out in Well A at two different chokes to understand flow behavior in wellbore and correlate with reservoir response. Based on these results, an intermediate choke was selected for production logging in Well B to observe any improvement in flow behavior. An integrated study of geomechanics, fracture performance and production logging resulted in deciding an optimal flow condition for the wells. Results are presented for a two well operation. Production logging results indicated that deeper intervals were producing higher compared to shallower layers, thereby validating the geomechanical model. Also, fissures were encountered during deep stage fractures, indicating potentially high production from reservoir from these stages due to better flow conduit. This was also confirmed from the production logging results. In Well N1, production logging data, in the lower choke, indicated sluggish and unstable flow behavior with the top three stages underperforming. However, at higher choke, a steady and uniform flow was observed. The production logging results were also observed to be in line with the obtained frac-operation parameters on the higher choke. However, an anomaly was observed in the second stage of Well N1, which is estimated to be as a result of fractures closing down due to higher stresses in shallower depths. Based on this, an intermediate choke was selected to flow Well N2 and record production log data to observe and evaluate the flow behavior at a different choke. The flow was still observed to be sluggish and unstable at the intermediate choke. Hence, a final decision was taken based on all the different conclusions to flow the wells at higher choke to maintain optimal frac stage performance and a uniform and steady flow. Rare geomechanical setting of reservoirs presented challenges in accurately characterizing them. The paper recognizes the versatility of the production logging tool in delivering and understanding both reservoir response and wellbore flow conditions. The integration of fracture response with production logging results enabled validation of the reservoir response and provided valuable insights into understanding the flow behavior inside the well, and finally optimizing well productivity.

Flow Behavior of a Centrifugal Compressor With Vaneless Diffuser at Design and Off Design Conditions

2012 ◽  
Author(s):  
Chuang Gao ◽  
Weiguang Huang ◽  
Haiqing Liu ◽  
Hongwu Zhang ◽  
Jundang Shi
Keyword(s):  
Centrifugal Compressor ◽  
Flow Behavior ◽  
Travelling Waves ◽  
Leading Edge ◽  
Pressure Oscillation ◽  
Rotating Stall ◽  
Vaneless Diffuser ◽  
Unstable Flow ◽  
Flow Recirculation ◽  
Static Performance

This paper concerns with the numerical and experimental aspects of both steady and unsteady flow behavior in a centrifugal compressor with vaneless diffuser and downstream collector. Specifically, the appearance of flow instabilities i.e., rotating stall and surge is investigated in great detail. As the first step, the static performance of both stage and component was analyzed and possible root cause of system surge was put forward based on the classic stability theory. Then the unsteady pressure data was utilized to find rotating stall and surge in frequency domain which could be classified as mild surge and deep surge. With the circumferentially installed transducers at impeller inlet, backward travelling waves during stall ramp could be observed. The modes of stall waves could be clearly identified which is caused by impeller leading edge flow recirculation at Mu = 0.96. However, for the unstable flow at Mu = 1.08, the system instability seems to be caused by reversal flow in vaneless diffuser where the pressure oscillation was strongest. Thus steady numerical simulation were performed and validated with the experimental performance data. With the help of numerical analysis, the conjectures are proved.

scholarly journals Analysis of Siphon String Application to Optimize Gas Lift Injection

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Sofani Muflih ◽  
Silvya Dewi Rahmawati
Keyword(s):  
Flow Regime ◽  
Production Rate ◽  
Flow Condition ◽  
Production Optimization ◽  
Font Size ◽  
Additional Advantage ◽  
Offshore Area ◽  
Well Model ◽  
Production Period ◽  
Gas Lift

<p><span style="font-size: small;"><span style="font-family: Times New Roman;"><em>B-</em><em>X</em><em> well is an oil producing well at Bravo field in Natuna offshore area, which was completed at IBS zone using 5-1/2 inch tubing size. </em><em>However, after several years of production period, the well’s production rate decreased due to reservoir depletion, and experienced gas lift performance problem indicated by unstable flowing condition (slugging flow). In year 2020, Siphon String installation is applied to the well in order to give deeper point of gas lift injection and better well’s production. The additional advantage by having smaller tubing size (insert tubing) is to reduce the slugging flow condition. The analysis of this siphon string installation at the B-X well, technically will be performed by evaluating gas lift performance and the flow regime inside the tubing using a Well Model simulator. The simulation was developed based on the real well condition. Several sensitivity analysis were done through several cases such as: variation in depth of gas lift point of injection, and the length of the siphon string. The simulation was required to evaluate the effectiveness of the existing installation, and to give better recommendation for the other well that has the same problem.  The result indicates that the depth of the current siphon string installation has been providing the optimum production rate, while the slugging flow condition will still be occurred at any given scenario of the siphon string depth due to the very low of well’s productivity. The similar procedure and evaluation can be implemented to other oil wells using gas lift injection located either in offshore or onshore field. </em></span></span></p><p><em><span style="font-family: Times New Roman; font-size: small;"> </span></em></p><p><em><span style="font-family: Times New Roman; font-size: small;">Keywords: Production Optimization, Siphon String, Flow Regime</span></em></p>

Modeling Unstable Flow Dynamics in Porous Media Associated With CO2 Sequestration

2008 ◽  
Author(s):  
Amir Riaz ◽  
Yildiray Cinar ◽  
Hamdi Tchelepi
Keyword(s):  
Porous Media ◽  
Multiphase Flow ◽  
Co2 Sequestration ◽  
Flow Behavior ◽  
Flow In Porous Media ◽  
Unstable Flow ◽  
Fundamental Physics ◽  
Macroscopic Models ◽  
Wide Range ◽  
Vertical Glass

Multiphase flow in porous media is fundamentally a microscopic process that governs the behavior of geologic scale processes. The application of existing (standard) macroscopic models to problems of geologic scale multiphase flow has proved to be unsatisfactory within a wide range of governing parameters. Our objective is to develop the missing link between the fundamental physics of multiphase flow at the pore-scale and the phenomenological representation of dynamic behaviors across a hierarchy of geologic scales. An essential prerequisite to such an analysis is a qualitative understanding of the flow behavior in terms of flow structures that exist for various parameter combination within the regime of CO2 sequestration. An experimental study addressing these objectives is presented. Experiments are carried out at the laboratory scale in a vertical glass-bead pack, in the parameter range of sequestration flows. Experimental results are interpreted with the help of invasion percolation models.

Compatibility Evaluation of BZ25-1 Crude Oils in Bohai Bay, China

2007 ◽  
Author(s):  
Jiaqiang Jing ◽  
Hongbin Niu ◽  
Lingbin Pan ◽  
Xiaoqin Xiong ◽  
Liwen Tan
Keyword(s):  
Crude Oil ◽  
Flow Behavior ◽  
Single Point ◽  
Production Optimization ◽  
Crude Oils ◽  
Bohai Bay ◽  
Major Objective ◽  
Offshore Production ◽  
Oil Mixtures ◽  
North Latitude

BZ25-1 oilfield is located in the southeast of Bohai bay which geographically lies between 119°00′ to 119°15′ east longitude and 38°10′ to 38°20′ north latitude. It has two oil blocks, including Shahejie (SHJ) waxy oil and Minghuazhen (MHZ) heavy oil, with six wellhead platforms WHPA∼WHPF and six submarine pipelines. Therein, the WHPC-WHPB and WHPB-SPM (Single Point Mooring) pipelines transport the mixture of the two produced crude oils. However, the mixing of the two oils will certainly bring out a change in their components and properties, which directly affects the safe operation of the submarine pipelines and offshore production facilities. Therefore, this paper compounds three kinds of MHZ/SHJ mixed oils with blending ratios of 1:1, 3:1 and 9:1, mainly studies how the components, rheological and thermophysical properties of the oil mixtures change with the blending ratio. The major objective of this study is to evaluate the compatibility of the two crude oils and provide a theoretical basis for the production optimization and risk elusion of the oilfield. The results of the study show that the components and properties of SHJ crude oil are quite different from those of MHZ oil, the flow behavior of SHJ oil is more sensitive to temperature. As MHZ oil in the compounds increases, the contents of asphaltene, resin, sulfur and carbon residue will increase except wax contents, their viscosities, densities and flash points will also increase, but their pour points, yield stresses, calorific values and other major thermophysical parameters will decrease. A blending ratio of 2∼7:1 for MHZ to SHJ crude oil can be concluded to make the properties of the compounds meet the safe and economic requirements of the subsea pipeline and offshore facility operations and ensure the compatibility of the mixed oils. In actuality, the field operations have confirmed that the recommended blending ratio is reasonable and practicable.

Measurement of Two-Dimensional Void Fraction Distributions of Rising Bubbles in a Simulated Sub-Channel by Wire-Mesh Sensors at Conditions of Forced Convective and Stagnant Flows

2017 ◽  
Author(s):  
Yota Suzuki ◽  
Yusei Tanaka ◽  
Taku Sakka ◽  
Akinori Sato ◽  
Kazuyuki Takase ◽  
...  
Keyword(s):  
Flow Condition ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Wire Mesh ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Fuel Rods ◽  
Fuel Rod ◽  
Stagnant Flow

Clarifying thermal-hydraulic characteristics in a nuclear reactor core is important in particular to enhance the thermo-fluid safety of nuclear reactors. Spacers installed in subchannels of fuel assemblies have the role of keeping the interval between adjacent fuel rods constantly. Similarly, in case of PWR the spacer has also the role as the turbulence promoter. When the transient event occurs, two-phase flow is generated by boiling of water due to heating of fuel rods. Therefore, it is important to confirm the two-phase flow behavior around the spacer. So, the effect of the spacer affecting the two-phase flow was investigated experimentally at forced convective flow condition. Furthermore, in order to improve the thermal safety of current light water reactors, it is necessary to clarify the two-phase flow behavior in the subchannels at the stagnant flow condition. So, the bubbly flow data around a simulated fuel rod were obtained experimentally at the stagnant flow condition. A wire-mesh sensor was used to obtain a detailed two-dimensional void fraction distribution around the simulated spacer and fuel rod. As a result of this research, the bubbly behavior around the simulated spacer and fuel rod was qualitatively revealed and also bubble dynamics in the sub-channels at the conditions of forced convective and stagnant flows were evaluated. The present experimental data are very useful for verifying the detailed three-dimensional two-phase flow analysis codes.

scholarly journals Complexity Reduction of Multiphase Flows in Heterogeneous Porous Media

SPE Journal ◽  
2016 ◽  
Vol 21 (01) ◽  
pp. 144-151 ◽  
Author(s):  
Mehdi Ghommem ◽  
Eduardo Gildin ◽  
Mohammadreza Ghasemi
Keyword(s):  
Porous Media ◽  
Model Reduction ◽  
Flow Behavior ◽  
Computational Cost ◽  
Heterogeneous Porous Media ◽  
Production Optimization ◽  
Dynamic Mode ◽  
Two Phase ◽  
Fine Grid ◽  
Mode Decomposition

Summary In this paper, we apply mode decomposition and interpolatory projection methods to speed up simulations of two-phase flows in heterogeneous porous media. We propose intrusive and nonintrusive model-reduction approaches that enable a significant reduction in the size of the subsurface flow problem while capturing the behavior of the fully resolved solutions. In one approach, we use the dynamic mode decomposition. This approach does not require any modification of the reservoir simulation code but rather post-processes a set of global snapshots to identify the dynamically relevant structures associated with the flow behavior. In the second approach, we project the governing equations of the velocity and the pressure fields on the subspace spanned by their proper-orthogonal-decomposition modes. Furthermore, we use the discrete empirical interpolation method to approximate the mobility-related term in the global-system assembly and then reduce the online computational cost and make it independent of the fine grid. To show the effectiveness and usefulness of the aforementioned approaches, we consider the SPE-10 benchmark permeability field, and present a numerical example in two-phase flow. One can efficiently use the proposed model-reduction methods in the context of uncertainty quantification and production optimization.

Molecular dynamics simulation on flow behavior of nanofluids between flat plates under shear flow condition

2010 ◽  
Vol 10 (2) ◽  
pp. 475-480 ◽  
Author(s):  
Jizu Lv ◽  
Wenzheng Cui ◽  
Minli Bai ◽  
Xiaojie Li
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Shear Flow ◽  
Flow Condition ◽  
Flow Behavior ◽  
Dynamics Simulation ◽  
Flat Plates

A computational fluid dynamics analysis of the wave soldering process

2015 ◽  
Vol 25 (5) ◽  
pp. 1231-1247 ◽  
Author(s):  
M.S. Abdul Aziz ◽  
M.Z. Abdullah ◽  
C.Y. Khor ◽  
M. Mazlan ◽  
A.M. Iqbal ◽  
...  
Keyword(s):  
Flow Behavior ◽  
Three Dimensional ◽  
Flow Profile ◽  
Content Type ◽  
Fountain Flow ◽  
Soldering Process ◽  
Wave Soldering ◽  
Computational Fluid Dynamics Analysis ◽  
Filling Time ◽  
Propeller Blades

Purpose – The purpose of this paper is to present a three-dimensional finite volume-based analysis on the effects of propeller blades on fountain flow in a wave soldering process and performs an experimental validation. Design/methodology/approach – Solder pot models with various numbers of propeller blades were developed and meshed by using hybrid elements and simulated by using the FLUENT fluid flow solver. The characteristics of the fountain, such as flow profile, velocity vector, filling time, and fountain advancement, were investigated. Molten solder (Sn63Pb37) material, a temperature of 250°C, and a propeller speed of 830 rpm were applied in the simulation. The predicted results were validated by the experimental fountain profile. Findings – The use of a six-blade propeller in a solder pot increased the fountain thickness profile and reduced the filling time. Moreover, a six-blade propeller design resulted in a stable fountain profile and was considered the best choice for current wave soldering processes. Practical implications – This study provides a better understanding of the effects of propeller blades on the fountain flow in the wave soldering process. Originality/value – The study explores the fountain flow behavior and provides a reference to the engineers and designers in order to improve the fountain flow of the wave soldering.

scholarly journals Preferred Site Selection Using GIS and AHP: Case Study in Bangka Island NPP Site

2021 ◽  
Vol 23 (1) ◽  
pp. 51
Author(s):  
Ari Nugroho ◽  
Eko Kusratmoko ◽  
Tito L. Indra
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Site Selection ◽  
Nuclear Power ◽  
Power Plants ◽  
Cooling System ◽  
Final Decision ◽  
Unstable Flow ◽  
Energy Agency

PREFERRED SITE SELECTION USING GIS AND AHP: CASE STUDY IN BANGKA ISLAND NPP SITE. Industrial growth affects the increasing demand for electricity in various places, this also occurs on the island of Bangka. So far, electricity supply has only been obtained from fossil fuel power plants with inadequate capacity, unstable flow and depending on fuel supplies from outside the island. For this reason, it is necessary to build a Nuclear Power Plant (PLTN) which is believed to be reliable and able to overcome these problems. In order to prepare a safe and economical nuclear power plant site, influential parameters such as population density, cooling system, land clearing, cut and fill, and granite for the foundation have been analyzed. The novelty of this analysis lies in 2 methods which gradually used before come up with a final decision, namely spatial analysis and pairwise comparison using Geographic Information Systems (GIS) and Analytical Hierarchy Process (AHP), respectively. The scope of study area is based on the site vicinity (1:5.000) scale, located in the districts of West and South Bangka. The siting process refers to the rules set by the International Atomic Energy Agency (IAEA). Based on the final results of the analysis using the expert choice program, the numerical weights for West Bangka and South Bangka were 0.709 and 0.291, respectively, with a consistency value of 0.03.

A Wind Tunnel Study of Heat Transfer Over Complex Terrain

2003 ◽  
Author(s):  
Michelle Pantoya ◽  
Kenneth Shifflett ◽  
Walter Oler ◽  
William Burton
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Wind Energy ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Flow Patterns ◽  
Atmospheric Conditions ◽  
Unstable Flow ◽  
Scaled Model ◽  
Atmospheric Flow

Maximizing wind energy resources requires a detailed understanding of atmospheric flow behavior over complex topography. The objective of this research is to examine unstable flow behavior over a three-dimensional topographic model, representative of mesa terrain that is common in West Texas. The goal is to develop an understanding of how unstable atmospheric conditions caused by surface heating affect boundary layer flow patterns in the natural environment. This objective was accomplished by experimentally monitoring transient thermal behavior of narrow band liquid crystals over a scaled model. Photographic data was collected as the heated model was subjected to a cooler flow field. The transient isotherms result from cooling as the model is exposed to flow in an atmospheric boundary layer wind tunnel. Results suggest that flow patterns associated with unstable conditions can be explained by increased wind speeds on the lee side of a mesa followed by vigorous mixing causing increased cooling rates around the mesa sides. The results could be used to improve the accuracy of numerical atmospheric flow models, assess the feasibility of developing wind turbine sites, and increase the knowledge-base in order to advance wind energy forecasting techniques.

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