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TEST YOURSELF

Task 1. Tell whether the sentences are true or false. Correct the false ones.
1. A reservoir rock concentrates gas and oil in a portion of a trap.
2. Structural traps are formed by a reservoir rock, such as a river channel sandstone or
limestone reef that is completely encased in shale.
3. Buried, tilted fault blocks can form large petroleum structural traps.
4. An angular unconformity can form a giant gas and oil primary stratigraphic trap when a
reservoir rock is terminated under an angular unconformity that is overlain by a seal.
5. Combination traps can have bald-headed structures.
6. Much of the weathered debris in deserts consists of unaltered rock and mineral fragments.
7. Chemical weathering also takes place in deserts.
8. Ephemeral streams carry water all the time.
9. Ephemeral streams have various names.
10. Wind does most of the erosional work in deserts.

Unit 10

PETROLEUM EXPLORATION – GEOCHEMICAL TECHNIQUES

Task 1. Read and memorize the following words:
application – застосування, використання proximity – близькість, сусідство
seep - просочуватись hydrocarbon halo- кільце з вуглеводню
tow – буксирувати, тягти water-sampling – забір проб води
sniffer – пристрій для забору та аналізу проб salinity - солоність
води або газу
vitrinite reflectance – відбиття вітриніту play – нафтогазоносний комплекс порід
trend – простягання родовища fairway – продуктивний пояс нафтових
покладів
prospect – об’єкт пошуку; розвідка; гірничі isopach map – мапа ізопахит
роботи з метою розвідки
configuration - форма closure – замкнута структура
breach – розрив, злам

Task 2. Read the following text, translate it into Ukrainian.

Text 1
Geochemistry is the application of chemistry to the study of the earth. Traces of
hydrocarbons in soil and water are often good indications of the proximity of a petroleum trap. In
an exploratory area, surface samples of waters and soils are taken. These samples are analyzed in
the laboratory with instruments such as gas chromatographs for minute traces of hydrocarbons.
Many subsurface petroleum reservoirs are leaky and have obvious seeps on the surface. Some
traps, however, are not as leaky and have only microseeps on the surface that cannot be detected
visually. The microseeps often occur in a pattern called a hydrocarbon halo that outlines the
subsurface trap. Seeps are also common in the ocean. Ships towing water-sampling equipment
and shipboard hydrocarbon-sensing devices called sniffers are used to detect their locations.
Water samples can be taken from subsurface rocks for chemical analysis. The subsurface
water salinity must be known before some wireline well log calculations, such as oil saturation,
can be accurately made. Traces of hydrocarbons in the subsurface waters of a dry hole could
indicate the presence of a petroleum reservoir in the area. Vitrinite reflectance is a method used
to determine the maturity of a source rock. Vitrinite is a type of plant organic matter often found
in black shale. The source rock sample is polished and then examined under a reflectance
microscope. The percentage of light reflected from the vitrinite is dependent on the maturity of