Petroleum reservoir fluids

In Section 5.2.8 we shall look at pressure-depth relationships, and will see that the relationship is a linear function of the density of the fluid. Since water is the one fluid which is always associated with a petroleum reservoir, an understanding of what controls formation water density is required. Additionally, reservoir engineers need to know the fluid properties of the formation water to predict its expansion and movement, which can contribute significantly to the drive mechanism in a reservoir, especially if the volume of water surrounding the hydrocarbon accumulation is large. 

Porous Media Packed beds of granular solids are one type of the general class referred to as porous media, which include geological formations such as petroleum reservoirs and aquifers, manufactured materials such as sintered metals and porous catalysts, burning coal or char particles, and textile fabrics, to name a few. Pressure drop for incompressible flow across a porous medium has the same quahtative behavior as that given by Leva s correlation in the preceding. At low Reynolds numbers, viscous forces dominate and pressure drop is proportional to fluid viscosity and superficial velocity, and at high Reynolds numbers, pressure drop is proportional to fluid density and to the square of superficial velocity. 

Petroleum engineers are traditionally involved in activities known in the oil industry as the front end of the petroleum fuel cycle (petroleum is either liquid or gaseous hydrocarbons derived from natural deposits—reservoirs—in the earth). These front end activities are namely exploration (locating and proving out the new geological provinces with petroleum reservoirs that may be exploited in the future), and development (the systematic drilling, well completion, and production of economically producible reservoirs). Once the raw petroleum fluids (e.g., crude oil and natural gas) have been produced from the earth, the back end of the fuel cycle takes the produced raw petroleum fluids and refines the.se fluids into useful products. 

Burcik, E.J., Properties of Petroleum Reservoir Fluids, International Human Resources Development Corp., Boston, 1979. 

Paralleling the corrosion problem is one involving compatibility of any well fluid with nonmetallic materials used in well completion apparatus. All injection wells and many producing wells are equipped with packers to isolate the casing annulus from the high temperature, pressure, and salinity characteristic of the petroleum reservoir environment. Conventional packers, as well as other well tools, utilize elastomeric materials to mechanically seal appropriate locations. 

Fig. 2.8. Example of a flush model. Fluid is pumped into a petroleum reservoir as a stimulant, or industrial waste is pumped into a disposal well. Unreacted fluid enters the formation, displacing the fluid already there.

In efforts to increase and extend production from oil and gas fields, as well as to keep wells operational, petroleum engineers pump a wide variety of fluids into the subsurface. Fluids are injected into petroleum reservoirs for a number of purposes, including ... 

In this chapter, in an attempt to devise methods for helping to foresee such unfavorable consequences, we construct models of the chemical interactions between injected fluids and the sediments and formation waters in petroleum reservoirs. We consider two cases the effects of using seawater as a waterflood, taking oil fields of the North Sea as an example, and the potential consequences of using alkali flooding (i.e., the injection of a strong caustic solution) in order to increase oil production from a clastic reservoir. 

Fig. 30.3. Variation in pH during simulated alkali floods of a clastic petroleum reservoir at 70 °C, using 0.5 N NaOH, Na2C03, and Na2Si03 solutions. Pore fluid is displaced by unreacted flooding solution at a rate of one-half of the system s pore volume per day.

A petroleum reservoir is discovered at 3000 psia and 130°F. If the reservoir fluid is represented by the phase diagram of Figure 2-32, will the reservoir contain liquid or gas What about the fluid of Figure 2-33 Figure 2—35 Figure 2-36 Which of the four fluids will exhibit retrograde behavior at reservoir conditions ... 

However, die major purpose of this chapter is to define and describe the five types of petroleum reservoir fluids. Each will be defined by reference to the shape of its typical phase diagram. Several rales of thumb will be given to assist in determining fluid type from normally available production data. Many of the producing characteristics of each type of fluid will be discussed. Ensuing chapters will address the physical properties of these five reservoir fluids,with emphasis on black oils, dry gases, and wet gases. 

API Recommended Practice For Sampling Petroleum Reservoir Fluids, API (1966) 44. 

Miscible fluid displacement (miscible displacement) is an oil displacement process in which an alcohol, a refined hydrocarbon, a condensed petroleum gas, carbon dioxide, liquefied natural gas, or even exhaust gas is injected into an oil reservoir, at pressure levels such that the injected gas or fluid and reservoir oil are miscible the process may include the concurrent, alternating, or subsequent injection of water. 

A foam, aqueous or non-aqueous, that is injected into a petroleum reservoir to improve the productivity of oil- or gas-producing wells. Some mechanisms of action for foam stimulation fluids include fracturing, acidizing to increase permeability, and diversion of flow. 

A furan containing resin has been used as an important component in a remedial method for controlling particulates within a petroleum reservoir <2007USP2007007010>. The process consists of placing an aqueous tackifying treatment fluid and a curable or non-curable polymer or resin into the unconsolidated zone of the reservoir, of which the furan resin is a constituent of the mixture. 

Properties of Petroleum Reservoir Fluids Table 4. Van der Weals Constants... 

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