Active words and word combinations.

To mention; to ensure; to prevent(from); set n.; to exert; to keep; condition; to vary; to include; to tolerate; to mean; adjacent; to impose; to create; considerable(ly); to consider; fracture n, v.; to occur; to dilute; detrimental; likelihood; to require; efficient; suction; to make mention;other

than; to be under consideration; under conditions; by means of; by no means of; in turn.

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Exercises

I.State the part of speech of the following words pointing out the word-building element.

Prevent – prevention; condition – conditional – conditionally; vary – variety – variable – various; include – including; exclude – excluding; tolerate – tolerance – tolerant; mean – meaning – meaningful – meaningless; create – creation – creative; consider – considerable – considerably; occur – occurrence; dilute – dilution – diluted; require – requirement – required; suck – suction.

II.Arrange the words given in a) and b) in pairs of synonyms.

а).To ensure, detrimental, set, to exert, to keep, to vary, fracture, to prevent, to include, to consider, to mention, to occur, likelihood, efficient, condition, to require.

b).To influence, to store, to change, to involve, not to allow, probability, to demand, effective, circumstances, to touch on smth, to guarantee, collection, to discuss, split, to take place, damaging.

III.Say it in English. If you are in difficulty, consult ex.2.

IV.Translate the following sentences paying special attention to the word 'mean' and its different derivatives.

1.The value of effective viscosity is meaningless unless the rate of shear at which it is measured

is specified. 2.Meaningful values of plastic viscosity and yield point can only be obtained by shearing to equilibrium at a specified speed. 3.There is no well-established means of predicting long-term gel strength. 4.This figure offers the best means of determining 'f 'when making hydraulic calculations for flow of mud in drilling wells. 5.The mean flow velocitiy required for turbulence increases with a decrease in the value of 'n'. 6.There is no means of diffrentiating between natural open fractures and induced fractures. 7.Fluid levels may be determined by means of an echometer or, less accurately, by counting the pump strokes required to fill the hole. 8.The change can be predicted by means of a model developed by Thomas Etal. 9.This point has considerable practical importance because it means that defloccunts such as complex phosphates and tannates should never be added to dispersed muds when drilling through water-sensitive formations. 10.Drilling fluids are by no means simple and have some rather unique properties. 11.But, on the other hand, reducing 'n' reduces the mean effective viscosity.

V.Translate into English using the active vocabulary.

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VI.Translate the text at sight and express its main ideas in 5-6 sentences either in English or in Russian.

Seal permeable formations.

Permeability refers to the ability of fluids to flow through porous formations; formations must be permeable for hydrocarbons to be produced. When the mud column pressure is greater than formation pressure, mud filtrate will invade the formation, and a filter cake of mud solids will be deposited on the wall of the wellbore. Drilling fluid systems should be designed to deposit a thin, low-permeability filter cake on the formation to limit the invasion of mud filtrate. This impoves wellbore stability and prevents a number of drilling and production problems. Potential problems related to thick filter cake and excessive filtration include 'tight' hole conditions, poor log quality, increased torque and drag, stuck pipe, lost circulation, and formation damage.

In highly permeable formations with large pore throats, whole mud may invade the formation, depending on the size of the mud solids. For such situations, bridging agents must be used to block the large openings so the mud solids can form a seal. To be effective, bridging agents must be about one-half the size of the largest opening. Bridging agents include calcium carbonate, ground cellulose and a wide variety of seepage-loss or other fine lost-circulation materials.

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Date: 2015-01-12; view: 1441