An Early-Time Model for Well Testing of a Hydrate-Capped Gas Reservoir

2007 ◽  
Author(s):  
Shahab Gerami ◽  
Mehran Pooladi-Darvish
Keyword(s):  
Early Time ◽  
Well Testing ◽  
Gas Reservoir ◽  
Time Model

A New View of Convective-Diffusive Transport Processes in the Arterial Intima

1991 ◽  
Vol 113 (3) ◽  
pp. 314-329 ◽  
Author(s):  
F. Yuan ◽  
S. Chien ◽  
S. Weinbaum
Keyword(s):  
Early Time ◽  
Transport Processes ◽  
Special Role ◽  
Diffusive Transport ◽  
Internal Elastic Lamina ◽  
Time Model ◽  
Feeding Experiments ◽  
Endothelial Surface ◽  
Extracellular Lipid ◽  
Order Of Magnitude

In this paper a new theoretical framework is presented for analyzing the filtration and macromolecular convective-diffusive transport processes in the intimal region of an artery wall with widely dispersed macromolecular cellular leakage sites, as proposed in the leaky junction-cell turnover hypothesis of Weinbaum et al. [11]. In contrast to existing convection-diffusive models, which assume that the transport is either 1-D, or convection is primarily in a direction normal to the endothelial surface, the present model considers for the first time the nonuniform subendothelial pressure field that arises from the different hydraulic resistances of normal and leaky endothelial clefts and the special role of the internal elastic lamina (IEL) in modulating the horizontal transport of macromolecules after they have passed through the leaky clefts of cells that are either in mitosis or demonstrate IgG labeling. The new theory is able to quantitatively explain the growing body of recent experiments in which an unexpectedly rapid early-time growth of the leakage spot has been observed and the longer time asymptotic behavior in which the leakage spot appears to approach an equilibrium diameter. The new theory also predicts the observed doubling in macromolecular permeability between EBA labeled blue and white areas when the frequency of leakage sites is doubled. This frequency for doubling of permeability, however, is an order of magnitude smaller than predicted by the author’s previous model, Tzeghai et al. [10], in which only convection normal to the endothelial surface was considered and the pressure was uniform in the intima. The longer time model predictions are used to explain the time scale for the formation of liposomes [4] in subendothelial tissue matrix in animal feeding experiments where it has been observed that the extracellular lipid concentration rises sharply prior to the entry of monocytes into the intima [45].

scholarly journals An Approach for Estimating Geothermal Reservoir Productivity under Access Limitations Associated with Snowy and Mountainous Prospects

2021 ◽  
Author(s):  
Mitsuo Matsumoto
Keyword(s):  
Early Time ◽  
Geothermal Field ◽  
Geothermal Reservoir ◽  
Well Testing ◽  
Reservoir Pressure ◽  
New Approach ◽  
Frequency Distributions ◽  
Arbitrary Time ◽  
Active Exploration ◽  
Time Limitations

This chapter describes an approach to estimate reservoir productivity during the active exploration and development of a geothermal prospect. This approach allows a reservoir model to be updated by overcoming the severe time limitations associated with accessing sites for drilling and well testing under snowy and mountainous conditions. Performed in parallel with the conventional standard approach, the new approach enables us to obtain a first estimate of the reservoir productivity at an early time and to make successful project management decisions. Assuming a practical geothermal field, the procedures of the new approach are demonstrated here in detail. Finally, frequency distributions for the expected production rates and changes in the reservoir pressure at an arbitrary time are obtained during an assumed operational period.

Early-Time Model of Laser Plasma Expansion

1971 ◽  
Vol 14 (9) ◽  
pp. 1905 ◽  
Author(s):  
Thomas P. Wright
Keyword(s):  
Laser Plasma ◽  
Early Time ◽  
Plasma Expansion ◽  
Time Model

scholarly journals Well Testing Model of Multiple Fractured Horizontal Well with Consideration of Stress-Sensitivity and Variable Conductivity in Tight Gas Reservoirs

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Zhongwei Wu ◽  
Chuanzhi Cui ◽  
Zhen Wang ◽  
Yingfei Sui ◽  
Peifeng Jia ◽  
...  
Keyword(s):  
Early Time ◽  
Stress Sensitivity ◽  
Late Time ◽  
Well Testing ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Pressure Derivative ◽  
Tight Gas Reservoirs ◽  
Fractured Horizontal Wells ◽  
Variable Conductivity

Multiple fractured horizontal wells have been widely used to develop unconventional tight gas reservoirs. Currently, many well testing models were established to study the performance of fractured horizontal wells in tight gas reservoirs. However, none of these models thoroughly takes stress-sensitivity of natural fractures and variable conductivity of artificial fractures into consideration. Based on the consideration of stress-sensitivity of natural fractures and variable conductivity of artificial fractures, a novel well testing model for fractured horizontal well in tight gas reservoirs is proposed. And the semianalytical solution of this new model is obtained by dividing the artificial fracture into different segments under the integrative methods of Laplace transformation, point source function, perturbation theory, superposition principle, and Stehfest numerical inversion. After validation, the semianalytical solution is consistent with that of Zerzar’s model (2004). Also, typical pressure and pressure derivative curves are plotted. According to typical curves, seven regimes can be derived, namely, bilinear flow, linear flow, early-time pseudoradial flow, biradial flow, intermediate-time pseudoradial flow, and pseudo-steady state interporosity flow, and late-time pseudoradial flow can be identified. In addition, this paper analyzes the impact on pressure and pressure derivative curves exerted by variable conductivity and stress-sensibility. The results show that variable conductivity mainly affects the early flow regimes, including bilinear flow, linear flow, and early-time radial flow, while the stress-sensitivity mainly affects the later flow regimes, including intermediate-time pseudoradial flow, pseudo-steady state interporosity flow, and late-time pseudoradial flow. The typical curves will ascend with the increasing of stress-sensitivity coefficient. The research provides a method for precise prediction of formation parameters and has a significant impact on the tight gas reservoir development.

scholarly journals The Researches on Reasonable Well Spacing of Gas Wells in Deep and low Permeability Gas Reservoirs

2018 ◽  
Vol 38 ◽  
pp. 01038
Author(s):  
Yu Bei Bei ◽  
Li Hui ◽  
Li Dong Lin
Keyword(s):  
Pressure Gradient ◽  
Low Permeability ◽  
Well Testing ◽  
Gas Wells ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Gas Field ◽  
Well Spacing ◽  
Start Up ◽  
Starting Pressure Gradient

This Gs64 gas reservoir is a condensate gas reservoir which is relatively integrated with low porosity and low permeability found in Dagang Oilfield in recent years. The condensate content is as high as 610g/m3. At present, there are few reports about the well spacing of similar gas reservoirs at home and abroad. Therefore, determining the reasonable well spacing of the gas reservoir is important for ensuring the optimal development effect and economic benefit of the gas field development. This paper discusses the reasonable well spacing of the deep and low permeability gas reservoir from the aspects of percolation mechanics, gas reservoir engineering and numerical simulation. considering there exist the start-up pressure gradient in percolation process of low permeability gas reservoir, this paper combined with productivity equation under starting pressure gradient, established the formula of gas well spacing with the formation pressure and start-up pressure gradient. The calculation formula of starting pressure gradient and well spacing of gas wells. Adopting various methods to calculate values of gas reservoir spacing are close to well testing' radius, so the calculation method is reliable, which is very important for the determination of reasonable well spacing in low permeability gas reservoirs.

scholarly journals Wellbore Storage Effects in Geothermal Wells

1980 ◽  
Vol 20 (06) ◽  
pp. 555-566 ◽  
Author(s):  
Constance W. Miller
Keyword(s):  
Flow Rate ◽  
Oil And Gas ◽  
Early Time ◽  
Geothermal Field ◽  
Effect Of Temperature ◽  
Well Testing ◽  
Well Test ◽  
Gas Field ◽  
Temperature Changes ◽  
Wellbore Storage

Abstract The early-time response in the well testing of a homogeneous reservoir customarily is expected to give a unit slope when the logarithm of pressure is plotted vs. the logarithm of time. It is shown that this response is a special case and that another nondimensional parameter must be defined to describe the set of curves that could take place for each value of the wellbore storage coefficient C . In addition, the effect of temperature changes along the bore is shown to increase the time when wellbore storage is important. Introduction The petroleum industry's technique of assessing oil and gas reservoirs by well testing has been extended to the geothermal field by a number of workers. However, at least two important differences between a geothermal field and an oil or gas field must be considered in analyzing geothermal well test data. First the kh/mu value of a geothermal field is usually much larger than that of an oil or gas field because the reservoir thickness h is greater in a geothermal field and the viscosity mu is smaller (k is the permeability). Second, heat loss in the wellbore, which can be ignored in oil and gas fields, is significant in geothermal bores.The concept of wellbore storage - which has been considered quite extensively and refined in such detailed studies as those of Agarwal et al., Wattenberger and Ramey, and Ramey - usually is treated as a boundary condition on the reservoir flow. The boundary condition used is (1) where dp w/dt is the flowing pressure change with time in the wellbore. However, dp w/dt is not necessarily independent of position in the well. When dp w/dt is dependent on the measurement point, a plot of log (p sf) vs. log (t) will not result in a unit slope at early times. This study will consider wellbore storage by looking at the flow in the well itself while treating the reservoir as simple homogeneous radial flow into the well.Heat loss from the well and temperature changes along the bore also have been ignored because oil and gas news can be treated as isothermal. Heat transfer from the well and heating of the fluid in the well is usually a very slow process. When very long times are considered, these temperature effects can become important. Once the early transient behavior is over and a semilog straight line of p sf vs. log(t) is expected in the pseudosteady region, temperature changes in the well can alter the slope of that line so that the slope would no longer be q mu/4 pi kh. The duration and importance of any temperature changes will be considered.A numerical model of transient two-phase flow in the wellbore with heat and mass transfer has been developed. It is used to investigate (1) the early-time interaction of the well flow with that of the reservoir and (2) the longer-time effect of temperature changes on the well test data. Concept of Wellbore Storage Wellbore storage is the capacity of the well to absorb or supply any part of a mass flow rate change out of a well/reservoir system. For a change in flow rate at the surface of the well, the sandface mass flow rate usually is expressed as (2) SPEJ P. 555＾

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