1. Text “Exploring of oil and gas”. Glossary

2. Equivalents of modal verbs

1). Read, translate and retell the text Text “Exploring of oil and gas”

Earth scientists in the petroleum industry – including geologists, geophysicists, geochemists and paleontologists – study what has happened to rocks that may be buried thousands of meters below surface, how those rocks were formed and affected by events stretching back millions of years, and how to identify traps where oil and gas accumulated within rock formations. An explorer may have a well-developed theory or intuition why an area should contain oil and gas. A first-hand look at outcrop geology and surface features sometimes helps to confirm the basic requirements – that there may be sedimentary rocks, potential reservoirs and hydrocarbon-bearing source in a sedimentary basin.

Within a basin, the explorer’s first step is to examine all the information already known about the area. This might include academic papers, surface geology observations, any wells drilled, data from relevant agencies or departments and previous exploration results from nearby or similar areas. Geophysicists can identify the structure, configuration, thickness and depth of new sedimentary basins by measuring slight variations in the Earth’s gravitational and magnetic fields and by measuring the time taken for seismic energy waves to pass through and be reflected from sedimentary layers.

In a typical trap, gas accumulates on the top of the reservoir as a “gas cap” over the oil, which in turn overlies the water-saturated zone in the reservoir. This occurs because natural gas is lighter than oil which is lighter than water. However, all three fluids are often intermingled in parts of the reservoir. Porosity is the ability of rock to hold oil and gas like water in a sponge. A trap requires three elements: a porous reservoir rock to accumulate the oil and gas – typically sandstones, limestones and dolomites an overlaying impermeable rock to prevent oil and gas from escaping source for the oil and gas, typical black waxy shales.

There are 6 common oil and gas traps: 1) thrust fault; 2) normal fault; 3) stratigraphic pinch-out; 4) reef; 5) anticlines; 6) salt dome. It is impossible to obtain the geophysical data from regulatory bodies, the seismic survey is required. In a seismic survey it is necessary to lay out a line or several lines of sensitive receivers, called geophones or jugs, on the ground. Then explosions or mechanical vibrations are created on the surface. The geophones record the energy reflected back as seismic waves from rock layers at various depths. Geophysicists and geologists examine the seismic data for the presence of suitable traps and for similarities with other petroleum-producing areas. If the results seem promising, they use the seismic data to pinpoint where to drill a well.

The aim of oil prospecting is discovering, geological and economic estimation, and preparation to oil development. Oil prospecting is done with the help of geological, geophysical, geochemical and drilling works in rational combination and consequence.

Answer the following questions:

What do the geologists, geophysicists, geochemists and paleontologists study?

What are the basic requirements for presence of oil and gas?

What is necessary to know about a basin?

How geophysicists can identify the structure, configuration, thickness and depth of new sedimentary basins?

In which for accumulates natural gas?

What is lighter: oil, water or gas?

How the seismic survey is conducted?

When it is possible to drill a well?

What is the aim of oil prospecting?

Exercise 1. Translate the following sentences into Kazakh:

1. Geologists, geophysicists, geochemists and paleontologists study what has happened to rocks that may be buried thousands of meters below surface and how to identify traps where oil and gas accumulated within rock formation. 2. All three fluids are often intermingled in parts of the reservoir. 3. The basic requirements of oil or gas presence must be sedimentary rocks, potential reservoirs and hydrocarbon-bearing source rocks in a sedimentary basin. 4. The explorer’s first step is to examine all the information already known about the area. 5. Geophysicists can identify the structure, configuration, thickness and depth of new sedimentary basins. 6. Gas accumulates on the top of the reservoir as a “gas cap” over the oil.7. The seismic survey is required when it is impossible to obtain the geophysical data from regulatory bodies. 8. In case if the results of seismic survey seem promising, they use the seismic data to pinpoint where to drill a well.

Read and learn by heart the following oil and gas glossary

accumulation: quantity of hydrocarbons found in the reservoir rock in an oil or gas field.

viscosity: ability of a liquid to flow at a given temperature.

volatility: ability of a liquid to evaporate.

alkylation: a chemical reaction that consists in fixing an alkyl radical onto a molecule.

mantle (earth's): the part of the earth between the crust and the central core.

mercaptan: molecules containing sulfur, with a low molecular weight and therefore very light.

appraisal well: a well drilled in order to evaluate the characteristics of a field.

treatment: set of procedures for separating the various components of the effluent and obtaining crude oil.

tubing: set of steel tubular elements in the center of the well, by which the effluent is evacuated to the surface.

sounding well: hole for obtaining data concerning the characteristics of a field.

sour crude: crude oil containing a substantial amount of sulfur.

strata: layers of rock making up a terrain.

petrochemicals: chemicals produced from petroleum. They are often manufactured as part of the refining process.

petroleum: from the Latin petroleum, meaning "stone oil", an inflammable oily liquid varying in color from yellow to black, consisting of widely varying hydrocarbons, found in sedimentary strata of the earth's crust.

platform: set of facilities rising above the sea, used to operate offshore fields.

porosity: ratio of the volume of interstices of a material to the volume of its mass. In oil fields, the oil and gas are contained in pores in the rock.

stratum of a terrain: mineral deposits in superposed layers.

stripping: a separation process that consists in injecting water steam into the distillation residue in order to recover the lightest molecules.

directional drilling: the most common drilling direction is vertical, but there may be various reasons for drilling obliquely.

distillation: the first step in the refining process. During distillation, crude oil is heated in the base of a distillation tower. As the temperature increases, the crude's various compounds vaporize in succession at their various boiling points, then rise to prescribed levels within the tower according to their densities, condense in distillation trays, and are drawn off individually for further refining. Distillation is also used at other points in the refining process to remove impurities.

subsoil: part of the earth's crust located below the surface.

turnaround: scheduled large-scale maintenance activity wherein an entire process unit is taken offstream for an extended period for comprehensive revamp and renewal.

assisted recovery: set of techniques for increasing the productivity of a field.

associated gas: gases present in the reservoir rock.

ballast tank: a tank intended to be filled with seawater to keep floating equipment stable.

barrel: unit of volume of crude oil (approximately 159 liters) in use in the oil industry, especially in the USA and the UK. Dates back to the days of sailing ships, when oil was shipped in casks.

bit: tool used in drilling to break up rock mechanically in order to penetrate the subsoil gradually. The bit will dig a circular hole.

blowout preventer (BOP): safety system that quickly closes a well in the course of drilling, to avoid accidental blowouts.

poduction well: well used when producing oil.

prospect: underground area in which geologists think there is a chance of finding oil.

reboiler: a special kind of heat exchanger used to put heat into a distillation column.

refinery: plant where crude oil is separated and transformed into marketable products.

catalysts: chemical compounds that facilitate or promote a reaction by their presence or action.

crude oil: a mixture of thousands of chemicals and compounds, primarily hydrocarbons. Crude oil must be broken down into its various components by distillation before these chemicals and compounds can be used as fuels or converted to more valuable products. Crude oil is classified as either sweet crude (sulfur content less than 0.5%) or sour crude, (at least 2.5% sulfur).

crude unit: the refinery processing unit where initial crude oil distillation takes place. See topping.

injection well: well used to inject water or gas, in order to maintain a field at pressure or bring it back under pressure.