The Development and Application of Virtual Flow Metering System in Offshore Gas Field

2014 ◽  
Author(s):  
Zhi Wang ◽  
Jing Gong ◽  
Haihao Wu ◽  
Qingpin Li
Keyword(s):  
Real Time ◽  
Flow Rate ◽  
Production System ◽  
Reservoir Characterization ◽  
Maximum Error ◽  
Production Rates ◽  
Gas Field ◽  
Flow Metering ◽  
Time Calibration ◽  
Subsea Production System

Well flow rate surveillance is essential for reservoir characterization and selecting potential activities and optimization production. Ideally, surveillance would be achieved using multiphase meters on each well, but generally it is not economically feasible especially for subsea production system. Therefore, the technology of virtual flow metering comes up. In this paper, the development and application of virtual flow metering system, used for determining production rates including gas oil and water flowrates in well, is discussed. Without any metering devices, the system, developed by China University of Petroleum, can automatically estimate single well and whole production rates every five minutes, only taking advantages of the instrumentations typically installed on wells. In hardware, the system is mainly made up of two servers, one of which in charge of communication, the other calculation. In software, the core algorithms are based on validated models of well hydraulics and flow through choke in oil industry. Also, the components and heat transfer influence is also taken into considered by their corresponding models. Based on these models, three independent algorithms are established for well flow rates prediction. Each algorithm is replicable for others in order to prevent measurement distortion and end caused by individual instruments faults. The value of estimated flow rate uncertainties in addition to real-time continuous well flowrate estimates is described. The flowrate basis on a daily or weekly reconciled by real-time calibration program basing on calculated uncertainties. The system practically applied in one subsea production system producing gas-condensate. In field commissioning, the system showed a great accuracy. The total mass flow rate and volumetric flowrates for each phase at standard conditions calculated with VMS showed a great agreement with the field data. The maximum error is below 10% and the averaged error is nearly 5%.

Proxy Model for Real-Time Estimation of Cool Down Time of Subsea Production System to Prevent Hydrates Formation

2021 ◽  
Author(s):  
Joseph Rizzo Cascio ◽  
Antonio Da Silva ◽  
Martino Ghetti ◽  
Martino Corti ◽  
Marco Montini
Keyword(s):  
Real Time ◽  
Production System ◽  
Field Data ◽  
Oil And Gas ◽  
Time Estimation ◽  
Integrated Approach ◽  
Proxy Model ◽  
Real Time Estimation ◽  
Subsea Production System ◽  
Formation Of Hydrates

Abstract Objectives/Scope The benefits of real-time estimation of the cool down time of Subsea Production System (SPS) to prevent formation of hydrates are shown on a real oil and gas facility. The innovative tool developed is based on an integrated approach, which embeds a proxy model of SPS and hydrate curves, exploiting real-time field data from the Eni Digital Oil Field (eDOF, an OSIsoft PI based application developed and managed by Eni) to continuously estimate the cool down time before hydrates are formed during the shutdown. Methods, Procedures, Process The Asset value optimization and the Asset integrity of hydrocarbon production systems are complex and multi-disciplinary tasks in the oil and gas industry, due to the high number of variables and their synergy. An accurate physical model of SPS is built and, then, used to develop a proxy model, which integrates hydrate curves at different MeOH concentration, being able to estimate in real time the cool down time of SPS during the shutdown exploiting data from subsea transmitters made available by eDOF in order to prevent formation of hydrates. The tool is also integrated with a user-friendly interface, making all relevant information readily available to the operators on field. Results, Observations, Conclusions The integrated approach provides a continues estimation of cool down time based on real time field data (eDOF) in order to prevent formation of hydrates and activate preservation actions. An accurate physical model of SPS is built on a real business case using Olga software and cool down curves simulated considering different operating shutdown scenarios. Hydrate curves of the considered production fluid are also simulated at different MeOH concentration using PVTsim NOVA software. Off-line simulated curves are then implemented as numerical tables combined with eDOF data by an Eni developed fast executing proxy model to produce estimated cool down time before hydrates are formed. A graphic representation of SPS behavior and its cool down time estimation during shutdown are displayed and ready to use by the operators on field in support of the operations, saving cost and time. Novel/Additive Information The benefits of real time estimation of the cool down time of SPS to prevent hydrates formation are shown in terms of saving of time and cost during the shutdown operations on a real case application. This integrated approach allows to rely on a continue, automatic and acceptably accurate estimate of the available time before hydrates are formed in SPS, including the possibility to be further developed for cases where subsea transmitters are not available or extended to other flow assurance issues.

The Research on the Factory Accept Test Technology of Subsea PLET

2014 ◽  
Vol 986-987 ◽  
pp. 1619-1623
Author(s):  
Xiao Lei Zhao ◽  
Le Ping Chu ◽  
Xing Wei Guo ◽  
Guo He Yu ◽  
Jin Yu Chen
Keyword(s):  
Deep Water ◽  
Production System ◽  
Oil And Gas ◽  
Development Mode ◽  
Gas Field ◽  
Oil And Gas Field ◽  
Subsea Production System ◽  
Offshore Oil And Gas ◽  
Embedded Type ◽  
Offshore Oil

With the development of offshore oil and gas field enters into deep water constantly, subsea production system has become the main development mode in deep water development. Pipeline End Termination (PLET) is common facilities in subsea production system and is used to provide subsea tieback interface. An embedded type PLET has been adopted in Panyu 35-1/35-2 Gas field with the water depth of 194 to 338 m. Factory Accept Test (FAT) is very important for the subsea production facilities, and the references is very limited due to technical security. This paper in detail states the flow chart, master equipment, purpose and precautions for each test of FAT for PLET, which collects great technology for the development of subsea production system.

The Study on the SIT Technology of Subsea ILM

2014 ◽  
Vol 986-987 ◽  
pp. 975-979
Author(s):  
Xiao Lei Zhao ◽  
Zhi Xing Wu ◽  
Le Ping Chu ◽  
Xing Wei Guo ◽  
Jin Yu Chen
Keyword(s):  
Deep Water ◽  
Production System ◽  
System Integration ◽  
Oil And Gas ◽  
Depth Range ◽  
Development Mode ◽  
Gas Field ◽  
Integration Test ◽  
Oil And Gas Field ◽  
Subsea Production System

With the development of offshore oil and gas field enters into deep water constantly, subsea production system has become the main development mode in deep water development. Subsea Inline manifold (ILM) is common facilities in subsea production system and is used to gather oil and gas from the side subsea wells. Two subsea ILMs has been adopted in Panyu 35-1/35-2 Gas field with water depth range from 194 to 338 m in South China Sea. System integration test (SIT) is very important for the subsea production facilities. This paper states the flow chart, master equipment, purpose and precautions for each test of ILM SIT, which collects great technology for the development of subsea production system.

Reliability Modelling of Subsea Cluster Manifolds Based on the Fault Tree Analysis

2016 ◽  
Author(s):  
Yingying Wang ◽  
Fangqiu Li ◽  
Menglan Duan ◽  
Houfa Liu ◽  
Jiandong Gu
Keyword(s):  
Production System ◽  
Oil And Gas ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Economic Losses ◽  
Gas Field ◽  
Tree Analysis ◽  
Reliability Modelling ◽  
South Sea ◽  
Subsea Production System

The cluster manifold becomes an essential part in a subsea production system and it has been widely used in the development of ultra-deepwater oil and gas fields. One hand, it can gather the production fluid from subsea wells. On the other hand, it can distribute water, gas and chemical agents from the floating production system to each subsea well. Hence, the failure of subsea cluster manifolds may not only lead to the stagnation of production wells and economic losses but also cause environmental pollution and human health in severe cases. Therefore, the reliability of subsea cluster manifolds is quite of importance and it should be studied for the safety service of the subsea production system. Based on the fault tree analysis (FTA), this paper will discuss the failure cause of six well slots subsea cluster manifolds in LiWan 3-1 gas field in China South Sea. Considering the pipeline structure, control system and flow assurance, the fault trees of subsea cluster manifolds are built. Meanwhile, the importance degrees of each elementary event are ranked orderly and the minimum cut sets are obtained through analyzing the structure important of the FTA. The failure major reasons are obtained and the preventive measures are proposed, which could have some guiding significance for the operations of subsea cluster manifolds system in China South Sea.

Troll Phase 3: The Next Step for a Groundbreaking Giant

2021 ◽  
Author(s):  
Bjørn Laastad ◽  
Knut Ellevog ◽  
Roger Oen Jensen ◽  
Torstein Tveit ◽  
Eirik Torgrimsen ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Value Creation ◽  
Value Chain ◽  
Production System ◽  
Phase 3 ◽  
Gas Field ◽  
Reduced Pressure ◽  
Final Design ◽  
Subsea Production System ◽  
Selection Phase

Abstract An important driver for maximizing value creation for the Troll Phase 3 gas project offshore Norway was to identify means to reduce the pressure drop in the value chain from the reservoir to the onshore terminal. Using a design-to-cost approach in the concept selection phase, this has affected design of the wells, subsea production system, pipeline and the new inlet separator on the Troll A platform; all of which have been designed to preserve the energy from the reservoir as much as possible. The final design has enabled a significant increase of the project value by accelerated gas deliveries, reduction of the energy consumption and thus lowering the CO2 emissions. Calculations show that 1 bar pressure drop in the Troll Phase 3 value chain increases the project NPV (8%, pretax) with approx. 45 Million USD and reduces the power consumption by 11 GWh/year. The well tubing size was increased to 9 5/8", reducing the required number of wells by ~40%. Factoring both wells and subsea facilities, this optimized well concept alone represents a total cost saving of nearly 300 million USD. The project has piloted a modification to the Vertical X-Mas Tree (VXT) design featuring an increase from 5 1/8" to a 7" production wing outlet to minimize the pressure drop across the subsea production system. This VXT design has become the new company standard for gas field developments. The big bore wells and subsea production system design also ensures acceptable gas velocities in the late production phase with low reservoir pressure. The total reduced pressure drop obtained through these and other measures is estimated to 19 bar, realizing a project NPV improvement of approx. 850 million USD (8%, pretax).

scholarly journals Dynamic Modelling and Simulation of a Multistage Flash Desalination System

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 522
Author(s):  
Qiu-Yun Huang ◽  
Ai-Peng Jiang ◽  
Han-Yu Zhang ◽  
Jian Wang ◽  
Yu-Dong Xia ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Dynamic Change ◽  
Seawater Temperature ◽  
Dynamic Modelling ◽  
Optimal Operation ◽  
Simultaneous Solution ◽  
Time Optimal

As the leading thermal desalination method, multistage flash (MSF) desalination plays an important role in obtaining freshwater. Its dynamic modeling and dynamic performance prediction are quite important for the optimal control, real-time optimal operation, maintenance, and fault diagnosis of MSF plants. In this study, a detailed mathematical model of the MSF system, based on the first principle and its treatment strategy, was established to obtain transient performance change quickly. Firstly, the whole MSF system was divided into four parts, which are brine heat exchanger, flashing stage room, mixed and split modulate, and physical parameter modulate. Secondly, based on mass, energy, and momentum conservation laws, the dynamic correlation equations were formulated and then put together for a simultaneous solution. Next, with the established model, the performance of a brine-recirculation (BR)-MSF plant with 16-stage flash chambers was simulated and compared for validation. Finally, with the validated model and the simultaneous solution method, dynamic simulation and analysis were carried out to respond to the dynamic change of feed seawater temperature, feed seawater concentration, recycle stream mass flow rate, and steam temperature. The dynamic response curves of TBT (top brine temperature), BBT (bottom brine temperature), the temperature of flashing brine at previous stages, and distillate mass flow rate at previous stages were obtained, which specifically reflect the dynamic characteristics of the system. The presented dynamic model and its treatment can provide better analysis for the real-time optimal operation and control of the MSF system to achieve lower operational cost and more stable freshwater quality.

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