EFFECT OF FOAMING AGENTS ON CRUDE OIL SYSTEM

EFFECT OF FOAMING AGENTS ON CRUDE OIL SYSTEM

ABSTRACT

This report entails the study of the effect of the foaming agents in the physio-chemical properties of the oil system, this report investigate if the addition of such foaming agents can improve production and also determines the properties of the crude oil and the foaming agents used. The properties investigated are Density, Specific Gravity, API gravity, viscosity, Surface Tension and Pour point before and after the addition of the foaming agents. The effects of foaming agents in crude oil: it increases density, viscosity and specific gravity of crude oil and decreases API gravity, surface tension, pour and cloud point of crude oil.  Statistical and graphical analysis were used to interpret the results of the experiments carried out. The results show that foaming agents increases oil density, oil viscosity, oil specific gravity and decreases oil API gravity, oil surface tension, oil cloud point and pour point.

The study would help petroleum engineers to understand the positive impact of foams in oil; especially during enhanced oil recovery (EOR).With such understanding and putting it into practical, production will be maximized.

CHAPTER ONE

INTRODUCTION

1.1 Crude Oil System

Crude Oil or Petroleum refers to any naturally-occurring flammable hydrocarbon mixture found in geologic formations, such as rock strata, formed through the heating and compression of organic material such as dead zooplankton and algae over a long period of time. Technically, the term petroleum only refers to crude oil, but sometimes it is applied to describe any solid, liquid or gaseous hydrocarbons. It is a hydrocarbon mixture having simple to most complex structures such as resins, asphaltenes etc. Crude oil can be refined to produce usable products such as gasoline, diesel and various forms of petrochemicals.

Crude oil is also a naturally occurring mixture, consisting of hydrocarbon with other element such as sulphur, nitrogen, oxygen, etc. appearing in the form of organic compounds which in some cases form complexes with metals. Elemental analysis of crude oil shows that it contains mainly carbon and hydrogen in the appropriate ration of six to one by weight. The mixture of hydrocarbon is highly complex, and the complexity increases with boiling range.

Crude oil is formed by bacterial transformation of Organic matter (carbohydrates/proteins/ animal origin) by decay in presence and/or absence of air into HC rich sediments by undergoing biological/physical and chemical alterations In its strictest sense, crude oil, but in common usage it includes all liquid, gaseous, and solid hydrocarbons. Under surface pressure and temperature conditions, lighter hydrocarbons methane, ethane, propane and butane occur as gases, while pentane and heavier ones are in the form of liquids or solids. However, in an underground oil reservoir the proportions of gas, liquid, and solid depend on subsurface conditions and on the phase diagram of the crude mixture.

1.2 Properties of crude oil system

Density

Density is defined as the mass per unit volume of a substance. It is most often reported for oils in units of g/mL or g/cm3, and less often in units of kg/m3. Density is temperature-dependent. Oil will float on water if the density of the oil is less than that of the water. This will be true of all fresh crude oils, and most fuel oils, for both salt and fresh water. Bitumen and certain residual fuel oils may have densities greater than 1.0 g/mL and their buoyancy behaviour will vary depending on the salinity and temperature of the water. The density of spilled oil will also increase with time, as the more volatile (and less dense) components are lost. After considerable evaporation, the density of some crude oils may increase enough for the oils to submerge below the water surface.

Two density-related properties of oils are often used: specific gravity and American Petroleum Institute (API) gravity. Specific gravity (or relative density) is the ratio, at a specified temperature, of the oil density to the density of pure water. The API gravity scale arbitrarily assigns an API gravity of 10° to pure water. API gravity is

Calculated as:

API gravity (o) = (141.5/ (specific gravity (60/60oF) - 131.5 ....................................... (1)

Oils with low densities, and hence low specific gravities, have high API gravities. The price of a crude oil is usually based on its API gravity, with high gravity oils commanding higher prices.

Pour Point

The pour point of an oil is the lowest temperature at which the oil will just flow, under standard test conditions. The failure to flow at the pour point is usually attributed to the separation of waxes from the oil, but can also be due to the effect of viscosity in the case of very viscous oils. Also, particularly in the case of residual fuel oils, Pour points may be influenced by the thermal history of the sample, that is, the degree and duration of heating and cooling to which the sample has been exposed. From a spill response point of view, it must be emphasized that the tendency of the oil to flow will be influenced by the size and shape of the container, the head of the oil, and the physical structure of the solidified oil. The pour point of the oils is therefore an indication, and not an exact measure, of the temperature at which flow ceases.

Viscosity

Dynamic Viscosity: Viscosity is a measure of a fluid's resistance to flow; the lower the viscosity of a fluid, the more easily it flows.

Like density, viscosity is affected by temperature. As temperature decreases, viscosity increases. The SI unit of dynamic viscosity is the millipascal-second (mPa∙s). This is equivalent to the former unit of centipoise (cp). Viscosity is a very important property of oils because it affects the rate at which crude oil will spread, the degree to which it will penetrate shoreline substrates, and the selection of mechanical spill countermeasures equipment.

Viscosity measurements may be absolute or relative (sometimes called 'apparent'). Absolute viscosities are those measured by a standard method, with the results traceable to fundamental units. Absolute viscosities are distinguished from relative measurements made with instruments that measure viscous drag in a fluid, without known and/or uniform applied shear rates.

Sulphur

The sulphur content of a crude oil is important for a number of reasons. Downstream processes such as catalytic cracking and refining will be adversely affected by high sulphur contents. Crude oil containing a high amount of the impurity (sulfur) is referred to as sour crude oil, when the total sulfur level in the oil is more than 0.5% the oil is called "sour”. The impurity needs to be removed before this lower-quality crude can be refined into petrol, thereby increasing the cost of processing.

The majority of the sulfur in crude oil occurs bonded to carbon atoms, with a small amount occurring as elemental sulfur in solution and as hydrogen sulfide gas. Sour oil can be toxic and corrosive, especially when the oil contains higher levels of hydrogen sulphide, which is a breathing hazard. At low concentrations the gas gives the oil the smell of rotting eggs. For safety reasons, sour crude oil needs to be stabilized by having hydrogen sulfide gas (H2S) removed from it before being transported by oil tankers. This results in a higher-priced gasoline than that made from sweet crude oil.

Basic Sediment and Water Content (BS&W)

Basic sediment and water (BS&W) is a technical specification of certain impurities in crude oil. When extracted from an oil reservoir, the crude oil contains some amount of water and suspended solids from the reservoir. The particulate matter is known as sediment or mud. The water content can vary greatly from field to field, and may be present in large quantities for older fields, or if oil extraction is enhanced using water injection technology.

TOPIC: EFFECT OF FOAMING AGENTS ON CRUDE OIL SYSTEM

Chapters: 1 - 5
Delivery: Email

Number of Pages: 81

Price: 3000 NGN

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