A New Model to Improve the Accuracy of Wellbore Pressure Calculation by Considering Gas Entrapment

2019 ◽  
Author(s):  
Shaowei Pan ◽  
Baojiang Sun ◽  
Zhiyuan Wang ◽  
Weiqi Fu ◽  
Yang Zhao ◽  
...  
Keyword(s):  
New Model ◽  
Wellbore Pressure ◽  
Pressure Calculation ◽  
Gas Entrapment

A Semi-Analytical Model for Predicting Horizontal Well Performances in Fractured Gas Reservoirs With Bottom-Water and Different Fracture Intensities

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Yongsheng Tan ◽  
Haitao Li ◽  
Xiang Zhou ◽  
Beibei Jiang ◽  
Yongqing Wang ◽  
...  
Keyword(s):  
Porous Medium ◽  
Horizontal Well ◽  
Bottom Water ◽  
Flow Model ◽  
Numerical Solutions ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
New Model ◽  
Well Completion ◽  
Wellbore Pressure

Numerical simulation and prediction studies on horizontal well performances in gas reservoir are foundation for optimizing horizontal well completion process. To gain more understanding on this theory, a steady-state reservoir model coupling with wellbore is developed in the fractured gas reservoirs with bottom-water and different fracture intensities to predict the horizontal well performances. Based on the equivalent flow assumption, the fractured porous medium is transformed into anisotropic porous medium so that the gas reservoir flow model can be developed as a new model that incorporates formation permeability heterogeneity, reservoir anisotropy, and gas reservoir damage. The wellbore flow model which considers pressure drops in the tubing is applied. We compare this paper model solutions for inflow profile along the well to the numerical solutions obtained from a commercial simulator (ECLIPSE 2011), and the result shows a very good agreement. Moreover, sensitive analysis, in terms of various linear densities of fractures, matrix permeability, fracture width, and wellbore pressure drop, is implemented. The results show that the new model developed in this study can obtain a more practical representation to simulate the horizontal wells performance in fractured gas reservoir with different fracture intensities and bottom-water, thus can be used to optimize the parameters in horizontal well completion of fractured gas reservoirs with different fracture intensities and bottom-water.

scholarly journals The near-wellbore pressure calculation model incorporating thermochemical effect

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 623-630
Author(s):  
Zhiqiang Tang ◽  
Qian Li ◽  
Hu Yin
Keyword(s):  
Pore Pressure ◽  
Drilling Fluid ◽  
Solute Concentration ◽  
Calculation Model ◽  
Hydraulic Pressure ◽  
Fluid Temperature ◽  
Wellbore Instability ◽  
Wellbore Pressure ◽  
Pressure Calculation ◽  
Tight Formation

The potential difference of hydraulic pressure, solute concentration and temperature between the drilling fluid and the formation fluid can induce the flow of solvent and cause changes in the pore pressure during drilling a tight formation, which may result in wellbore instability. According to the continuity equation of fluid, the pore pressure calculation model considering the effect of thermochemical coupling is established and the solution of the pore pressure in the Laplace domain is given. Using this model, the effects of the temperature, solute concentration and viscosity of drilling fluid on the pore pressure around the wellbore are simulated. The results show that, when the wellbore pressure is higher than the formation pressure and the solute concentration of the drilling fluid is larger than that of the formation fluid, the near-wellbore pore pressure will decrease first and then increase during drilling a tight formation, and increasing the drilling fluid temperature will decrease the pore pressure. Increasing the solute concentration of the drilling fluid can inhibit the increase of the pore pressure.

Detailed Modeling of Drilling Fluid Flow in a Wellbore Annulus While Drilling

2013 ◽  
Author(s):  
Evgeny Podryabinkin ◽  
Valery Rudyak ◽  
Andrey Gavrilov ◽  
Roland May
Keyword(s):  
Numerical Solutions ◽  
Drilling Fluid ◽  
Full Range ◽  
Newtonian Fluids ◽  
Rheological Parameters ◽  
Flow Mode ◽  
Drilling Fluids ◽  
New Model ◽  
Wellbore Pressure ◽  
Analytical Approaches

To produce a well safely, the wellbore pressure during drilling must be in a range that prevents collapse yet avoids fracturing. This range is often called “the operating window”. Exceeding the limits of this range can trigger wellbore instability or initiate well control incidents. Pressure prediction requires an understanding of the hydrodynamics processes that occur in a borehole while drilling. Describing these processes is complicated by many factors: the mud rheology is usually non-Newtonian, the flow mode can be laminar or turbulent, and the drillstring can rotate and be positioned eccentrically. Known semi-analytical approaches cannot account for the full range of fluid flows that can arise during drilling. These techniques don’t take into account all factors. Accurate numerical simulation of the flow of drilling fluids is a means to describe the fluid behavior in detail. For numerical solutions of hydrodynamics equations a unique algorithm based on a finite-volume method and a new model of turbulence for non-Newtonian fluids was developed. The model considers string rotation and eccentricity of the drillstring. Newtonian and non-Newtonian fluids as described by the Herschel–Bulkley rheological model have been implemented. Data obtained via systematic parameter studies of the flow in a borehole are available for fast determination of parameters like pressure drop, velocity field, and stresses corresponding to any drilling condition. Applying the new model for the annulus flow and comparing the results to the parallel plate flow approximation enabled us to quantify the error made due to the approximated solution for non-Newtonian fluid rheology. The difference between the solutions grows as the annular gap increases. This situation is a function of the rheological parameters. Secondary flow effects can only be seen when applying the new solution method.

The Hitachi Model HS-8 Electron Microscope

1967 ◽  
Vol 25 ◽  
pp. 238-239
Author(s):  
H. Akabori ◽  
K. Nishiwaki ◽  
K. Yoneta
Keyword(s):  
Electron Microscope ◽  
New Model ◽  
Predecessor Model

By improving the predecessor Model HS- 7 electron microscope for the purpose of easier operation, we have recently completed new Model HS-8 electron microscope featuring higher performance and ease of operation.

516: A Simplified Method to Estimate the Absolute Renal Uptake of 99MTC-DMSA: Evaluation with a New Model using the Radioactivity of Nephrectomy Specimens as Reference

2005 ◽  
Vol 173 (4S) ◽  
pp. 140-141
Author(s):  
Mariana Lima ◽  
Celso D. Ramos ◽  
Sérgio Q. Brunetto ◽  
Marcelo Lopes de Lima ◽  
Carla R.M. Sansana ◽  
...  
Keyword(s):  
New Model ◽  
Renal Uptake ◽  
Simplified Method ◽  
The Absolute

Analyzing Stochastic Dependence of Cognitive Processes in Multidimensional Source Recognition

2014 ◽  
Vol 61 (5) ◽  
pp. 402-415 ◽  
Author(s):  
Thorsten Meiser
Keyword(s):  
Cognitive Processes ◽  
Model Complexity ◽  
Multinomial Model ◽  
Stochastic Dependence ◽  
New Model ◽  
Multinomial Processing Tree ◽  
Cognitive States ◽  
The Family ◽  
Tree Models ◽  
Flexible Framework

Stochastic dependence among cognitive processes can be modeled in different ways, and the family of multinomial processing tree models provides a flexible framework for analyzing stochastic dependence among discrete cognitive states. This article presents a multinomial model of multidimensional source recognition that specifies stochastic dependence by a parameter for the joint retrieval of multiple source attributes together with parameters for stochastically independent retrieval. The new model is equivalent to a previous multinomial model of multidimensional source memory for a subset of the parameter space. An empirical application illustrates the advantages of the new multinomial model of joint source recognition. The new model allows for a direct comparison of joint source retrieval across conditions, it avoids statistical problems due to inflated confidence intervals and does not imply a conceptual imbalance between source dimensions. Model selection criteria that take model complexity into account corroborate the new model of joint source recognition.

From Harm to Help: A New Model of Feminist Therapy

1986 ◽  
Vol 31 (2) ◽  
pp. 108-109
Author(s):  
Alexandra G. Kaplan
Keyword(s):  
Feminist Therapy ◽  
New Model

The Promise of a New Model of Theistic Psychology

PsycCRITIQUES ◽  
2004 ◽  
Vol 49 (Supplement 13) ◽  
Author(s):  
Paul E. Priester
Keyword(s):  
New Model

Effective Evaluation: A New Model Becomes a Classic

1993 ◽  
Vol 38 (4) ◽  
pp. 406-407
Author(s):  
Donald B. Yarbrough ◽  
Monika Schaffner
Keyword(s):  
New Model ◽  
Effective Evaluation
Sign in / Sign up

Export Citation Format

Share Document