The effect of the methyl substituent on the interaction between the exchangeable cations in alkaline-earth-metal X zeolites and methyl-substituted amines has been examined by measuring the thermal desorption spectra and the infrared absorption spectra of adsorbed amines. The methylamines adsorbed on NaX, SrX, CaX and MgX gave two types of desorption peaks (a and 8). The temperature range of the a peak, which appears on the lower-temperature side,
Original SPE manuscript received for review Feb. 16, 1993. Revised manuscript received May 31, 1995. Paper peer approved July 6, 1995. Paper (SPE 24493) first presented at the 1992 SPE Abu Dhabi Petroleum Conference and Exhibition held in Abu Dhabi, May 18-20. SPE Production & Facilities, November 1995. Summary Flow in horizontal wells and two-phase flow interaction with the reservoir were investigated experimentally and theoretically. Two-phase flow behavior has been recognized as one of the most important problems in production engineering. We designed and constructed a new test facility suitable for acquiring data on the relationship between pressure drop and liquid holdup along the well and fluid influx from the reservoir. For the theoretical work, an initial model was proposed to describe the flow behavior in a horizontal well configuration. The model uses the inflow-performance-relationship (IPR) approach and empirical correlations or mechanistic models for wellbore hydraulics. Although good agreement was found between the model and experimental data, a new IPR apart from the extension of Darcy's law must be investigated extensively to aid in the proper design of horizontal wells. Introduction Literature Review. Horizontal wells have become attractive for the production of thin-layer reservoirs, naturally fractured reservoirs, and reservoirs with gas- or water-coning problems. Horizontal wells can improve the inflow performance of these reservoirs and produce more oil with smaller pressure drawdowns than conventional vertical wells because of enhancement of the reservoir contact and negative skin factors. The flow behavior in the horizontal section, which has an increasing flow rate along it caused by influx from the reservoir, and the relationship between the pressure drop and the influx have been recognized as important problems in production engineering. The flow behavior and the relationship between the pressure drop and the influx are also essential items of information in the proper design of a horizontal well; however, these factors have not been clarified yet. Despite the increasing number of publications pertaining to drilling and reservoir aspects of horizontal wells, few studies have been conducted on this subject. Dikken presents a simple analytical method that links a single-phase turbulent liquid flow in a horizontal wellbore to an isothermal reservoir flow and predicts the frictional pressure gradient along the horizontal wellbore. He concludes that the reduced drawdown caused by turbulent flow along the wellbore may result in the total production rate reaching a certain critical value as a function of wellbore length. Islam and Chakma present a physical model based on experimental results that may describe multiphase flow through perforations in a horizontal well. Heavy or mineral oil, water, and air were used. However, the interaction between the flow behavior in the horizontal well and the reservoir was not taken into account in their experiments. Ihara conducted an experimental and theoretical investigation on this subject with a small-scale test facility that features a 25.4-mm-ID, 7.9-m-long horizontal well-test section. This test facility closely simulates the interaction and enables the acquiring of data, except liquid holdup. No other studies were found on this subject by the end of 1991. Problem Description. The assumption of a constant pressure along a horizontal wellbore, which is used often for well-test analysis and reservoir simulation for horizontal wells, must be examined carefully. Neither a uniform-flux nor a uniform-pressure boundary condition in the wellbore is realistic. Some pressure drop from the upstream end of a horizontal wellbore to the downstream end is essential to maintain fluid flow within the wellbore (Fig. 1). This condition is particularly true when two-phase flow, including a compressible gas phase, is encountered in the wellbore. For the production of single-phase liquid, pressure drop along the wellbore may be neglected, except for a high-viscosity liquid, high reservoir permeability of a few darcies, or high production rates in excess of a few thousand reservoir barrels per day. The flow behavior in a horizontal wellbore differs from that in a regular pipe. The wall roughness of a horizontal well can be much higher than that of a regular pipe because of perforations or slots. The influx along the wellbore can change the pressure drop in the wellbore. This pressure distribution not only affects the production behavior, but also is influenced by the well completion and well configuration. The best approach would probably be to measure such flow characteristics as pressure drop and flow rates in an actual horizontal well and to compare them with physical models to see whether the models predict the data. However, it is very difficult to insert pressure transducers at both ends of a horizontal wellbore, to change the operating conditions, and to calibrate the data. There is also no reliable way to measure multiphase flow rates along a horizontal wellbore accurately. Thus, a representative laboratory-scale experimental procedure is required. The following describes an elaborate experimental program conducted to generate the data for flow in a horizontal wellbore, including interaction with a reservoir. A physically based mechanistic model to predict the flow behavior is presented and evaluated with the experimental data. Experimental Program Test Facility. A large-scale test facility was designed and constructed to simulate the main features of a horizontal well configuration. The test facility is shown schematically in Fig. 2. In a horizontal wellbore, fluids flowing in the wellbore are disturbed by fluids entering into it at various points along its length. This fluid entry in a direction that is perpendicular to the main flow in the wellbore may create flow disturbances. The test facility enables us to acquire the data pertaining to the interaction between the reservoir and the horizontal-well piping system. Reservoir pressure, reservoir resistance to flow into the wellbore, and flow through perforations can be simulated. The test section is a 54.9-mm-ID, 105.03-m-long horizontal test loop constructed of stainless steel pipe. Strictly speaking, horizontal wells are normally drilled parallel to the reservoir bedding plane. Thus, horizontal wells are not horizontal but have many bends and curves as the wells follow the bedding planes. The experiments are limited to the horizontal configuration. Other inclination angles will likely be taken into account in further studies. However, a proposed model mentioned later takes into consideration the effect of inclination angle on the flow behavior. Air and water are used as the gas and liquid phases of the reservoir fluids. The reservoir pressure is simulated by a gas-driven air/water supply vessel. The compressed air at the top of the vessel provides the input air-flow driving force to the supply loops as well as the driving force for water. The air and water go into the air and water supply loops, respectively, to provide the same pressure at every injection point. Mass transfer between the gas and liquid phases will not occur in a low-pressure air/water system of less than 1,070 kPa. Thus, it is necessary to simulate free gas at undersaturated reservoir conditions by adjusting air flow rate into the wellbore. The variation of reservoir resistance to flow is simulated by opening and closing a needle valve for air and a globe valve for water located in the injection lines. Flow through the perforations is simulated by the injection equipment. The test loop leads to a separator, where the pressure can be adjusted up to 710 kPa. The water is then circulated back to the supply vessel by a water pump.
Furthermore, for undefined mixtures, such as coal liquids, a method of determining the extent of association is required. The slope of the molecular weight versus concentration curve appears to be a parameter which can be used to characterize this association, although at present the results cannot be used to quantitatively correct for errors in enthalpy correlations. ACKNOWLEDGMENTSThe authors wish to thank the Office of Fossil Energy, Department of Energy for support of this work, Contract DE-AC22-81 PC40787. NOTATION g = grams of solute G = grams of solvent constant defined in Eq. 2 (K g/gmol) = latent heat of fusion of the solvent (J/g) = apparent molecular weight of the solute (g/gmol) = freezing-point of the solvent ("R or K) = observed depression of the freezing point (K) = molecular weight at infinite dilution (g/gmol) = slope of molecular weight versus solute concentration = composition of solute in benzene (cc/2Occ solvent)
The purpose ofthis smdy is to develop the dynamic model ofthe f()mation ofdensity gradicnt layer in the siorage tank due to the injection ofdense nuid through a horizontal bottom − fi 【 I nozzle with inclined upwardjet mixing into a tank partially filled with fluid . An analytical modcl was propo 匚ed on the fbmation of density gradienUayer , and the density prome was obtained experimentally using a smalttank and salt watcr , ne analytical rcsults was i皿 good agreement with the experirnental results .
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