TY - THES

T1 - Application of Multiflash Pipesim Software to Determine WAT (Case Study)

AU - Ghadiri Asli, Hosein

N1 - no embargo

PY - 2019

Y1 - 2019

N2 - The potential for wax formation and deposition along subsea production systems pose a severe flow assurance risk. During early stages of a field development (when information is limited), the risk needs to be quantified in order to develop preliminary mitigation strategies. It is agreed that the risks associated wax deposition can be mitigated only if wax appearance temperature [WAT] is accurately measured or predicted. Up to date, there are two methods that can be used to determine the wax appearance temperature, laboratory based method and simulation based method. Wax laboratory measurements alone are not sufficient to quantify the wax deposition risk because of the uncertainties associated with the laboratory results and the difficulties to apply the actual field production condition, in contrast using the simulation alone as reliable source will not help to quantify the risk associated with wax deposition. Therefore, it was necessary to think outside the box in order to come up with ideal method in which both the laboratory measurements and simulation results are utilized and combined , this will help to define the most effective engineering decisions in shorter time. Hence, prime purpose of this thesis is to develop a workflow that can be used to evaluate the wax deposition risk during the development phase for any field by integrating laboratory measurements with Multiphase Flow Simulator. Several researches have demonstrated that, when comparing the results obtained with the default wax model coefficients (no benchmarking) and the benchmarked models, the predictions are significantly different. Similar deviations are observed with the predictions based on wax data reported by different laboratories (for the same fluid sample). Since the overall design and operating strategy are highly dependent on wax deposition rates. Therefore, the discrepancies between the wax data measured by different laboratories and predicted by different models are required to be checked and standardized. Thus, the developed workflow is designed in a manner that several additional steps are taken into account which has not been considered before. It will consist, tuning fluids models, benchmarking the wax deposition models (using the measured wax deposition rates), and conducting wax deposition simulations with the benchmarked models. The resulting wax deposition predictions can be used to evaluate various design options during development stage and for devising operating strategies throughout the life of the field (such as insulation requirements, injection of paraffin inhibitor, pigging operations, etc.).The other remarkable benefits of the proposed workflow is to validate the laboratory test data with the result obtained from Multiflash software, in order to bridge the gap between the laboratory wax test measurements and flow assurance modelling. In order to assess the applicability and benefits of the proposed workflow, a case study has been performed using actual data. The case study proves that the workflow can be used.

AB - The potential for wax formation and deposition along subsea production systems pose a severe flow assurance risk. During early stages of a field development (when information is limited), the risk needs to be quantified in order to develop preliminary mitigation strategies. It is agreed that the risks associated wax deposition can be mitigated only if wax appearance temperature [WAT] is accurately measured or predicted. Up to date, there are two methods that can be used to determine the wax appearance temperature, laboratory based method and simulation based method. Wax laboratory measurements alone are not sufficient to quantify the wax deposition risk because of the uncertainties associated with the laboratory results and the difficulties to apply the actual field production condition, in contrast using the simulation alone as reliable source will not help to quantify the risk associated with wax deposition. Therefore, it was necessary to think outside the box in order to come up with ideal method in which both the laboratory measurements and simulation results are utilized and combined , this will help to define the most effective engineering decisions in shorter time. Hence, prime purpose of this thesis is to develop a workflow that can be used to evaluate the wax deposition risk during the development phase for any field by integrating laboratory measurements with Multiphase Flow Simulator. Several researches have demonstrated that, when comparing the results obtained with the default wax model coefficients (no benchmarking) and the benchmarked models, the predictions are significantly different. Similar deviations are observed with the predictions based on wax data reported by different laboratories (for the same fluid sample). Since the overall design and operating strategy are highly dependent on wax deposition rates. Therefore, the discrepancies between the wax data measured by different laboratories and predicted by different models are required to be checked and standardized. Thus, the developed workflow is designed in a manner that several additional steps are taken into account which has not been considered before. It will consist, tuning fluids models, benchmarking the wax deposition models (using the measured wax deposition rates), and conducting wax deposition simulations with the benchmarked models. The resulting wax deposition predictions can be used to evaluate various design options during development stage and for devising operating strategies throughout the life of the field (such as insulation requirements, injection of paraffin inhibitor, pigging operations, etc.).The other remarkable benefits of the proposed workflow is to validate the laboratory test data with the result obtained from Multiflash software, in order to bridge the gap between the laboratory wax test measurements and flow assurance modelling. In order to assess the applicability and benefits of the proposed workflow, a case study has been performed using actual data. The case study proves that the workflow can be used.

KW - Wax Appearance Temperature

KW - Flow protection

KW - Wax deposit

KW - Wachsablagerung

KW - Fließsicherung

M3 - Master's Thesis

ER -