Reservoir flow

Fig. 12. HDR reservoir flow test at Fenton Hill, New Mexico (1992) (39). (a) Injection pressure profile ( ) and a sismic limit (-------) (b) injection ( )...

The operation of a typical fluid power system is illustrated in Figure 40.1. Oil from a tank or reservoir flows through a pipe into a pump. An electric motor, air motor. 

Observations of the arrival of the C02 acid front at different wells clearly demonstrates that there is a great deal of heterogeneity in the reservoir. Furthermore, the arrival of waters which are undersaturated with respect to calcite suggests that single producing wells are recovering waters with widely different C02 contents. These observations have important implications for the interpretation of produced water compositions in complex reservoirs it must be done in conjunction with detailed reservoir flow models. 

Micropumps based on piezoelectrics are made of pumping chambers that are actuated by three piezoelectric lead zirconate titanate disks (PZT). The pump consists of an inlet, pump chambers, three silicon membranes, three normally closed active valves, three bulk PZT actuators, three actuation reservoirs, flow microchannels, and outlet. The actuator is controlled by the peristaltic motion that drives the liquid in the pump. The inlet and outlet of the micropump are made of a Pyrex glass, which makes it biocompatible. Gold is deposited between the actuators and the silicon membrane to act as an upper electrode. Silver functions as a lower electrode and is deposited on the sidewalls of the actuation reservoirs. In this design, three different pump chambers can be actuated separately by each bulk PZT actuator in a peristaltic motion. 

Figure 3.3 A schematic presentation of the chip holder, reservoirs, flow control, high pressure connections, and optical detection in NLC [8].

Assuming a typical oil reservoir containing medium heavy crude oil and employing a reservoir flow rate of 0.26 m/day. The solution viscosity could be increased to 30 mPa s by adding about 1000 pg/rril (0.1%) partially hydrolyzed polyacrylamide polymer (at pH 8.5). The interfacial tension could be reduced to 0.1 mN/m by adding 1% sodium carbonate, which reacts with the crude oil to produce natural surfactant. The interfacial tension could be further reduced to 0.03 mN/m by adding 0.1% ethoxylated alcohol sulfate cosurfactant. 

Generate a statistical description (means, trends, variances and correlations) of the reservoir flow field. Doing this requires a rather massive amount of data primary sources are well data, outcrop analogues, seismic profiling and "type functions based bn stratification types and depositional environment. In an ideal case, there should be such a statistical description for every input variable for the reservoir simulator. 

Macroscopic experiments such as core flooding have been used to obtain relative permeabilities, dispersion coefficients, and other variables relevant to reservoir flow. However, they cannot reveal details of how immiscible phases interact on the pore level. Instead visual experiments have been used to elucidate microscopic flow mechanisms. The latter approach is taken here with experiments using a novel flow cell and state-of-the-art video equipment. The pore level phenomena observed provide a basis for the proper modeling of two-phase flow through porous media at high capillary numbers. 

The experience from Rock Creek and Siggins Field suggests that tests may be substantially more informative if maximum use of pressure tests and multiple tracers is made to determine reservoir flow patterns before a site is selected and a test is designed, instead of being used as part of the test after a site has been selected. 

Nelson and Pope (24) described these phase relationships and demonstrated that phases observed in laboratory test tube experiments also form and are transported in a porous medium subjected to a chemical flood at reservoir flow rates. Chemical floods continuously maintained in a type II(+) phase environment recovered substantially more residual oil than those maintained in a type II(-) environment. 

An important part of modelling the impact of fault damage zones of reservoir flow relies on the ability to... 

Pentamidine can cause bronchospasm and airway irritation in humans [9]. This appears to be caused by the pentamidine moiety itself, because similar irritation is seen in nonisethionate salts of pentamidine. Because P. carinii habitats the alveolus and because of the potential adverse effects of pentamidine on the airways, pentamidine ideally should be aerosolized in a small particle, between 1 and 2 pm. Studies that make in vitro comparisons of nebulizers cannot be valid unless the particle sizes are identical. The present state of knowledge cannot allow determination of the most effective device because not all the devices have been comparatively tested in humans [10,11]. The optimal particle size for alveolar deposition is between 1 and 3 pm, with 1 pm achieving more peripheral distribution and less airway distribution [12-14]. However, 19% of particles as small as 2 pm still impact in the tracheobronchial regions. The ideal device should have a particle size of 1 -2 pm with a high output. Particles between 0.5 and 1 pm have relatively less alveolar deposition than particles between 1 and 2 pm. Other features, such as reservoirs, flows, and external filters, may also be important [9]. However, any nebulizer with particle sizes, on average, greater than 8 pm would not deliver adequate dmg to the alveoli. 

Fig. 7.17 Simplified version of the sulphur cycle (after Brimblecombe et al. 1989). (a) Sulphur cycle as it is thought to have been prior to any major anthropogenic influence, (b) Sulphur cycle as it was in the mid-1980s. Units for inter-reservoir flows are in TgSyU1 (i.e. 1012gSyr 1). With permission from the Scientific Community on Problems of the Environment—SCOPE, John Wiley Sons Ltd.

This section discusses diffusion coefficients in a bulk phase and a porous medium. It also briefly introduces a statistical representation of diffusion. Diffusion is less significant in reservoir flow than dispersion and their mechanisms are different, but the discussion of diffusion provides an analog to the formulation of dispersion. 

At relatively low flow rates, the convective component is negligible, and the diffusion component is dominant. As shown in Figure 2.3, at high flow rates, the diffusion component is negligible, and the convective component is dominant. Between these exttemes, both components contribute to the overall dispersion process, and this is the regime commonly encountered in reservoir flow processes. Note that the dimensionless Peclet number is defined in Figure 2.3 as... 

Now we compare the values of diffusion coefficient and convective dispersion coefficient. For a typical value of Fidp = 0.36 cm, the ratio of convective term to diffusion term is vFidp/Do = (1 m /86400 s)(0.0036 m)/(4 x 10 ° mVs) = 105. Referring to Figure 2.3, we can see that the mechanism of transport in typical reservoir flow is convection dominated. 

Finally, we compare the values of longitudinal and transverse dispersion coefficients at typical reservoir flow conditions. Using Eqs. 2.53 and 2.54, we have... 

Huang and Yu (2002) observed that emulsification was not completely reversible. When the dynamic IFT reached ultralow, emulsification occurred. Even when dynamic IFT went up, emulsified oil droplets did not easily coalesce. In alkaline flooding, emulsification is instant, and emulsions are very stable. From this emulsification point of view, the dynamic minimum IFT plays an important role in enhanced oil recovery. From the low IFT point of view, we may think we should use equilibrium IFT because reservoir flow is a slow process. However, the coreflood results in the Daqing laboratory showed that when the minimum dynamic IFT reached 10 mN/m level and the equilibrium IFT was at 10 mN/m the ASP incremental oil recovery factors were similar to those when the equilibrium IFT was 10 mN/m (Li, 2007). One explanation is that once the residual oil droplets become mobile owing to the instantaneous minimum IF F, they coalesce to form a continuous oil bank. This continuous oil bank can be move even when the IFT becomes high later. Then for this mechanism to work, the oil droplets must be able to coalesce before the IFT becomes high. It can be seen that it will be more difficult for such a mechanism to function in field conditions rather than in laboratory corefloods. This mecha-... 

Gunter, G. W. et al. 1997. Early determination of reservoir flow units using an integrated petrophysical model. Paper SPE 38679 presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas (5-8 October). 

Fig. 5. Diagram of Varian Model 8500 pumping system, a = valve to pressurize the reservoir, c = solvent reservoir, -flow valve, f = pressure transducer, g = pneumatic valve...

Rock Mechanical Properties Reservoir Flow Properties Geometry Parameters ... 

The velocities encountered in groundwater and jpetroleum reservoir flow are generally small enough for the kinetic energy terms in Bernoulli s equation to be neglected. Furthermore, the flow is almost always laminar, so that S is described by Darcy s equation (Eq. 12.16). Thus, Bernoulli s equation for this situation becomes... 

The 1973 ASCE paper presents a conceptual model to alleviate flood damages due to overtopping failures of future small earthfill dams including the erosion pattern. The potential reduction in the reservoir release due to the proposed erosion retarding layer is also investigated. A method to determine the optimum layer location is provided so as to minimize the maximum possible reservoir release due to a gradually-breached earth dam. The transient reservoir flow is simulated by a numerical model based on the solution of the one-dimensional Saint-Venant equations, which are solved by the method of characteristics subjected to appropriate boimdaiy conditions. The numerical simulation provides the reduction in release discharge in terms of various parameters. 

At typical reservoir flow rates (say from 1 to lOft/day, which is 0.35-3.5 x 10 cm/s), the dispersive term usually dominates over the diffusion term by... 

Solve for the flow from a straight fracture using any reservoir flow simulator. How singular is the velocity obtained at the tips How does volume flow rate compare with analytical results What is the effect of tip error on total flow rate Repeat your calculations with different mesh distributions for different assumed parameters. 

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