Late Life Field Management with Instrumentation Failure. Modelling Predictions and Successful Validations of Late Life Subsea Gas Condensate System Using Historical Field Data

2021 ◽  
Author(s):  
Lawrence Khin Leong Lau ◽  
Kun An ◽  
Wu Jun Tong ◽  
Song Wang ◽  
Zhi Wei Yue ◽  
...  
Keyword(s):  
Field Data ◽  
Pressure Fluctuations ◽  
Flow Characteristics ◽  
Late Life ◽  
Flow Regimes ◽  
Gas Condensate ◽  
Well Production ◽  
Water Cut ◽  
Instrumentation Failure ◽  
Condensate System

Abstract Depleting reservoir pressure, increasing water cut and decreasing overall system production leading to increased liquid holdup are among the key challenges for typical late life gas condensate production system. This paper elucidates modelling details of a late life offshore subsea gas condensate system and how the findings are implemented and validated with actual field data for successful outcomes. There is only one subsea well remain in operation with relatively long subsea flowlines. Subsea pressure and temperature transducers are out of service as the asset approaches the end of design life. In this context, flow assurance team has taken the modelling approach in order to minimize cost and to maximize values. Detailed transient multiphase thermohydraulics models are developed and benchmarked against field data. Historical field data over the past two years are utilized in order to predict the trend for key parameters such as well production rates and water to gas ratio (WGR). Matrix of simulation including the predictions of slugging flow regimes are carried out for the entire flow path, from reservoir characteristics descriptions at bottom hole, through flow regimes analysis at topsides slug catcher. Three categories of operation characteristics, namely the low risk, medium risk, and high risk production periods are identified. It is predicted that the system would start to fall into slugging flow regimes from 2 months onwards with final production end date of after 10 months. This is shared with wider team such that operations and base management teams are informed with predicted multiphase flow characteristics for the remaining production life. As such, gas supply succession plan can be executed in time to ensure uninterrupted downstream commercial agreement. Feedbacks from operations team revealed accurate predictions of such analysis, including slugging flow phenomenon which was associated with flow and pressure fluctuations, was observed in field as predicted by the study. More importantly, the production cut-off date is accurately predicted 10 months ahead and within the accuracy of ± 1 week. This study demonstrated how historical field data, coupled with detailed transient multiphase thermohydraulics modelling, can be utilized for offshore gas condensate production predictions during late life. Without transducers and/or virtual metering data feed, production end date can be accurately predicted based on key parameters analysis. This is particularly valuable for supply succession planning and is deemed a successful case study with significant positive outcomes which can be used as reference for other gas condensate assets.

Model Prediction of Critical Gas Rate With Water-Cut Reversal Effect

2021 ◽  
Author(s):  
Merit P. Ekeregbe
Keyword(s):  
Model Prediction ◽  
Field Data ◽  
Dynamic Test ◽  
Late Life ◽  
Well Performance ◽  
Critical Rate ◽  
Reservoir Performance ◽  
Rate Prediction ◽  
Liquid Load ◽  
Water Cut

Abstract Accurate prediction of gas critical rate is critical to the successful management of gas wells. This paper covers the prediction of gas critical rate and presents limitations of old models with gas condensate wells with water-cut reversal. Comparison of prediction methods or models with this new method will be explained using field data of condensate wells. The effect and relation of water-cut with critical gas rate determination will be presented and the best method that universally meets changing conditions of the well will be tested with field data. Any method that must be acceptable must meet the dynamics of the well. No static model can predict accurately a dynamic well and reservoir performance. The old models of critical gas rate prediction show a static outlook, probably see the beginning of the well-life and cannot predict correctly when the fluid phases change in gravity. The late life prediction of the well performance is much more critical than the early life when the well has sufficient energy. The production envelope is more critical at depletion than at when the reservoir energy just kick. Therefore, any model prediction must be dynamic. The results from the old models show that they fail the dynamic test of the well performance. This limitation makes those model unusable in a late life of the well when water cut increases. This study has revealed a method or a model for critical rate prediction that is accurate throughout the life of the well. The effect of water cut reversal is well tracked with this new model whereas the static nature of other models predicts a wrong minimum rate at a liquid load up rate. The field data reveals that the dynamic nature of well and reservoir performance can only be understood dynamically.

Model Prediction of Critical Gas Rate with Water-Cut Reversal Effect

2021 ◽  
Author(s):  
Merit P. Ekeregbe
Keyword(s):  
Model Prediction ◽  
Field Data ◽  
Dynamic Test ◽  
Late Life ◽  
Well Performance ◽  
Critical Rate ◽  
Reservoir Performance ◽  
Rate Prediction ◽  
Liquid Load ◽  
Water Cut

Abstract Accurate prediction of gas critical rate is critical to the successful management of gas wells. This paper covers the prediction of gas critical rate and presents limitations of old models with gas condensate wells with water-cut reversal. Comparison of prediction methods or models with this new method will be explained using field data of condensate wells. The effect and relation of water-cut with critical gas rate determination will be presented and the best method that universally meets changing conditions of the well will be tested with field data. Any method that must be acceptable must meet the dynamics of the well. No static model can predict accurately a dynamic well and reservoir performance. The old models of critical gas rate prediction show a static outlook, probably see the beginning of the well-life and cannot predict correctly when the fluid phases change in gravity. The late life prediction of the well performance is much more critical than the early life when the well has sufficient energy. The production envelope is more critical at depletion than at when the reservoir energy just kick. Therefore, any model prediction must be dynamic. The results from the old models show that they fail the dynamic test of the well performance. This limitation makes those model unusable in a late life of the well when water cut increases. This study has revealed a method or a model for critical rate prediction that is accurate throughout the life of the well. The effect of water cut reversal is well tracked with this new model whereas the static nature of other models predicts a wrong minimum rate at a liquid load up rate. The field data reveals that the dynamic nature of well and reservoir performance can only be understood dynamically.

scholarly journals Effect of Air Injection on the Internal Flow Characteristics in the Draft Tube of a Francis Turbine Model

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1182
Author(s):  
Seung-Jun Kim ◽  
Yong Cho ◽  
Jin-Hyuk Kim
Keyword(s):  
Flow Rate ◽  
Draft Tube ◽  
Pressure Fluctuations ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Air Injection ◽  
Low Flow ◽  
Francis Turbine ◽  
Navier Stokes ◽  
Vortex Rope

Under low flow-rate conditions, a Francis turbine exhibits precession of a vortex rope with pressure fluctuations in the draft tube. These undesirable flow phenomena can lead to deterioration of the turbine performance as manifested by torque and power output fluctuations. In order to suppress the rope with precession and a swirl component in the tube, the use of anti-swirl fins was investigated in a previous study. However, vortex rope generation still occurred near the cone of the tube. In this study, unsteady-state Reynolds-averaged Navier–Stokes analyses were conducted with a scale-adaptive simulation shear stress transport turbulence model. This model was used to observe the effects of the injection in the draft tube on the unsteady internal flow and pressure phenomena considering both active and passive suppression methods. The air injection affected the generation and suppression of the vortex rope and swirl component depending on the flow rate of the air. In addition, an injection level of 0.5%Q led to a reduction in the maximum unsteady pressure characteristics.

Studying demulsifier reactants for crude oil processing facilities

2021 ◽  
pp. 90-104
Author(s):  
L. V. Taranova ◽  
A. G. Mozyrev ◽  
V. G. Gabdrakipova ◽  
A. M. Glazunov
Keyword(s):  
Crude Oil ◽  
Bottom Water ◽  
Oil Content ◽  
Optimal Consumption ◽  
Residual Oil ◽  
Well Production ◽  
Oil Processing ◽  
Water Cut ◽  
Required Quality

The article deals with the issues of improving the quality of highly watered well production fluid processing using chemical demulsifier reactants at crude oil processing facilities; the analysis of the use of the reactants at the Samotlor field has been made. The article presents the results of the study of the effectiveness of the "Hercules 2202 grade A" and "SNPH-4460-2" demulsifiers in comparison with the indicators of oil and bottom water processing achieved in the presence of the reactants used at existing facilities; their optimal consumption has been determined. The study has shown that the selected demulsifiers provide the required quality of the oil and water under processing at the considered oil processing facilities and can be used along with the basic reactants for these facilities. On the basis of total indicators, the best results have been achieved using "Hercules 2202 grade A" with the improved indicators of water cut and residual oil content in water by 33.9 % and 2.8 % while reducing the reactant consumption by 9.7 % compared to the basic demulsifier.

Flow and Energy Loss Downstream of Rectangular Sharp-Crested Weirs for Free and Submerged Flows

2021 ◽  
Author(s):  
Mahmud R. Amin ◽  
Nallamuthu Rajaratnam ◽  
David Z. Zhu
Keyword(s):  
Energy Loss ◽  
Flow Regime ◽  
Analytical Study ◽  
Flow Characteristics ◽  
Turbulent Jets ◽  
Flow Regimes ◽  
Impinging Jet ◽  
Relative Energy ◽  
Surface Flow ◽  
Upper Stage

Abstract This work presents an analytical study of the flow and energy loss immediately downstream of rectangular sharp-crested weirs for free and submerged flows, using the theory of plane turbulent jets and the analysis of some relevant studies. The flow regimes downstream of the sharp-crested weir is characterized as the impinging jet and surface flow regimes. Based on the flow characteristics and the downstream tailwater depths, each flow regime is further classified, and the relative energy loss equation is developed. It is found that significant energy loss occurs for the regime of supercritical flow and the upper stage of impinging jet flow. The energy loss for the submerged flow regime is minimal.

scholarly journals How will climate change modify river flow regimes in Europe?

2013 ◽  
Vol 17 (1) ◽  
pp. 325-339 ◽  
Author(s):  
C. Schneider ◽  
C. L. R. Laizé ◽  
M. C. Acreman ◽  
M. Flörke
Keyword(s):  
Climate Change ◽  
River Flow ◽  
Anthropogenic Impacts ◽  
Flow Characteristics ◽  
Flow Regimes ◽  
Temperate Climate ◽  
Climate Zone ◽  
Natural Flow ◽  
The Mediterranean ◽  
Boreal Climate

Abstract. Worldwide, flow regimes are being modified by various anthropogenic impacts and climate change induces an additional risk. Rising temperatures, declining snow cover and changing precipitation patterns will interact differently at different locations. Consequently, in distinct climate zones, unequal consequences can be expected in matters of water stress, flood risk, water quality, and food security. In particular, river ecosystems and their vital ecosystem services will be compromised as their species richness and composition have evolved over long time under natural flow conditions. This study aims at evaluating the exclusive impacts of climate change on river flow regimes in Europe. Various flow characteristics are taken into consideration and diverse dynamics are identified for each distinct climate zone in Europe. In order to simulate present-day natural flow regimes and future flow regimes under climate change, the global hydrology model WaterGAP3 is applied. All calculations for current and future conditions (2050s) are carried out on a 5' × 5' European grid. To address uncertainty, bias-corrected climate forcing data of three different global climate models are used to drive WaterGAP3. Finally, the hydrological alterations of different flow characteristics are quantified by the Indicators of Hydrological Alteration approach. Results of our analysis indicate that on the European scale, climate change can be expected to modify flow regimes remarkably. This is especially the case in the Mediterranean (due to drier conditions with reduced precipitation across the year) and in the boreal climate zone (due to reduced snowmelt, increased precipitation, and strong temperature rises). In the temperate climate zone, impacts increase from oceanic to continental. Regarding single flow characteristics, strongest impacts on timing were found for the boreal climate zone. This applies for both high and low flows. Flow magnitudes, in turn, will be predominantly altered in the Mediterranean but also in the Northern climates. At the end of this study, typical future flow regimes under climate change are illustrated for each climate zone.

Coating of Particles in Spouted Bed: Flow Regime and Stability

2010 ◽  
Vol 660-661 ◽  
pp. 573-579
Author(s):  
J.L. Vieira Neto ◽  
J.E. Borges ◽  
Claudio Roberto Duarte ◽  
Marcos A.S. Barrozo
Keyword(s):  
Power Spectrum ◽  
Pressure Fluctuations ◽  
Flow Regimes ◽  
Main Flow ◽  
Agricultural Products ◽  
Soybean Seeds ◽  
Spouted Bed ◽  
Cyclical Motion ◽  
The Stability ◽  
The Many

The coating and encapsulating of particles presents many applications in the chemical, pharmaceutical, food and agricultural products industries. Among the many applications of seeds coating, the enlargement of small seeds is included in order to facilitate the planting, the addition of herbicides, fungicides, fertilizers, micronutrients and inoculation. The spouted bed has often been used in studies related to the coating of particles, due to the cyclical motion of the material, which promotes a fast axial mixture of particles and an excellent gas-particle contact. In this work, the coating of soybean seeds with inoculum and micronutrients in spouted bed has been studied. The different flow regimes were investigated using the pressure fluctuations and power spectrum. The results of the present work showed that it was possible to identify the main flow regimes and to analyze the influence of the coating in the stability of those regimes.

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