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Zhai Y.,China University of Petroleum - Beijing | Wang Z.,China University of Petroleum - Beijing | Zhang Q.,China University of Petroleum - Beijing | Gao Q.,GWDC Engineering Research Institute
Applied Mechanics and Materials | Year: 2013

Calculation and optimization of hydraulic parameters remains one of major challenges when planning and drilling deepwater wells. Based on traditional drilling theory and the characteristics of deepwater drilling, the particularity of deepwater drilling hydraulic parameters design is analyzed. According to the different features of the riser segment, inclined segment and horizon segment, the method for calculating the optimum displacement is proposed in segmental way. Besides, an applicable optimization method is presented for designing deepwater drilling parameters. The predicted value exhibits good agreement with measured value in drilling field, and it has practically guiding significance to deepwater drilling hydraulic parameters design. © (2013) Trans Tech Publications, Switzerland.

Wu Y.,China University of Petroleum - Beijing | Wu X.,China University of Petroleum - Beijing | Wang Y.,China University of Petroleum - Beijing | Yuan Y.,GWDC Engineering Research Institute
International Journal of Control and Automation | Year: 2013

A new eccentric annular leakage model for rod pump with Couette-Poiseuille flow is proposed. This model considers not only the effect of pressure fluctuation yielded by overlying liquid on the plunger, but also the direction of Couette flow leakage, which is consistent to the direction of Poiseuille flow leakage. Furthermore, the consideration of the fluctuation effect is proved to be necessary, and the determination of the direction is justified. An analysis on the relationship between leakage rate, pumping speed and pump depth is developed. The results are consistent with the field observations. And at last, the proposed model is proved to be more accurate when compared with the testing data.

Zhang Q.,China University of Petroleum - Beijing | Wang Z.-M.,China University of Petroleum - Beijing | Wang X.-Q.,China University of Petroleum - Beijing | Zhai Y.-J.,China University of Petroleum - Beijing | And 2 more authors.
Applied Mechanics and Materials | Year: 2013

Over the past two decades, the modeling of flow in a perforated pipe with influx through orifices on the pipe wall has been recognized as an important issue especially in the field of horizontal wells. This article provides a careful analysis of the current models that are all based on laboratory experiments. Results show that the models can be mainly divided into two categories according to the number of openings perforated along the conduit surface. One is developed based on experiments with one single perforation, which includes Asheim model, Yalniz model and Zhou model. This kind of models could not be readily used to calculate the pressure losses of the actual flows such as horizontal wellbore flow without modification and thus has a poor applicability. Another is based on experiments with multiple perforations, which includes Siwon model, Yuan model, Ouyang model, Su model and Wang model. Although these models are appropriate for the pressure losses prediction along the completion, all of them are semi-empirical, which implies the huge complexities of developing accurate ones. In addition, Siwon model and Yuan model are relatively the most comprehensive models which could be used to account for the various factors affecting the flow behaviors in perforated pipes. The equivalent friction factor due to pipe wall perforations of Su model has a more theoretical foundation with more room for improvement. This analysis about the models regarding the pressure drops in perforated pipes indicates that more efforts should be made to acquire a better understanding of the complex flow mechanism and build a unified model which is more theoretical and robust. © (2013) Trans Tech Publications, Switzerland.

Yang P.,GWDC Engineering Research Institute | Yin F.,GWDC Engineering Research Institute
Drilling Fluid and Completion Fluid | Year: 2012

A high temperature seawater base clay-free drilling fluid system is developed based on the optimized additives, such as viscosifier, filtrate reducer, lubricant and inhibitor. The performance evaluation results show that drilling fluid system is stable at 150°C, provides high anti-pollution capacity of bentonite and good lubricating performance, moreover, the core penetration rate recovery rate is more than 90% that can protect reservoirs effectively.

Li J.,GWDC Engineering Research Institute | Yang P.,GWDC Engineering Research Institute | Guan J.,GWDC Engineering Research Institute | Sun Y.,GWDC Engineering Research Institute | Kuang X.,GWDC Engineering Research Institute
Shiyou Kantan Yu Kaifa/Petroleum Exploration and Development | Year: 2014

To meet the demand of ultra deep well drilling and shale gas well drilling, organic clay and a oil-based filtrate reducer were developed and a whole oil-based drilling fluid formula was optimized. The performance of organic clay, oil-based filtrate reducer and the whole oil-based drilling fluid were evaluated in laboratory, and the whole oil-based drilling fluid was applied in drilling process for further test of its performance. Long carbon chain quaternary ammonium salt was used as modifying agents when synthesizing organobentonites. Oil-based filtrate reducer was synthesized with monomers of lignite and amine class. The laboratory tests show that the organic clay can effectively increase the viscosity of oil-based drilling fluid and the oil-based filtrate reducer can reduce the fluid loss. Their performances were better than additives of the same kind at home and abroad. The organic clay and oil-based filtrate reducer had great compatibility with the other additives in oil-based drilling fluid. Based on the optimal additives addition amount tests, the whole oil-based drilling fluid formula was determined and the test results show that the performances of the whole oil-based drilling fluids with various densities were great. The laboratory tests show that the oil-based drilling fluid developed was high temperature resistant, even at 200 ℃, as density varies from 0.90 to 2.0 g/cm3, it still held good performance with only a little fluid loss, good inhibition, great anti-pollution, and good reservoir protection performance. Field application result shows that the performance of the oil-based drilling fluid is stable with great ability to maintain wellbore stability and lower density than the water-based drilling fluid; drilling bits can be used much longer and the average penetration rate is increased; the oil-based drilling fluid can satisfy the drilling requirements.

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