Unit 4 Fluid or gas influx

Ex.1 Learn the new words.

borehole - буровая скважина; шпур	formation – формация, порода
fluid - жидкость	circumstances – обстоятельства
influx – приток	force – сила
efflux – истечение, отток	solid – твердый, твердое вещество
thixotropic - тиксотропный	drill string - бурильная колонна, технологический инструмент
a gel – гель gelation -1) загустевание 2) структурообразование (бурового раствора)	differential pressure - перепад давления, относительное давление yield stress- предел текучести; напряжение пластического течения
exterior- наружный, внешний	to operate – действовать, работать
properly – тщательно	longitudinal - продольный
interface - граница	axial - осевой; по направлению оси
drill bit - головка бура	transition period – переходный период
non-drip paint – краска без подтеков	thyrotrophic – тиреотропный
subsequent - дальнейший, последующий	relevant - соответствующий, имеющий отношение

Ex.2 Read and translate the text.

Fluid or gas influx

When drilling a borehole for a well it is desirable to be informed when fluid is passing through the walls of the borehole between the borehole itself and the formation. It is necessary to know in order to continue the drilling process properly and efficiently.

It has now been discovered that in certain circumstances data about the influx or efflux of fluid can be gained by observing the pressure within the borehole. This observation should be carried out not when the drill is actually operating but when it is still and the drilling fluid is not being pumped. The reason for this is that the drilling fluid is thyrotrophic like a non-drip paint, and when not disturbed it will form a gel.

Surprisingly, a gelled fluid can accurately transmit the force created by moving fluids at the interface between the borehole and the earth formation displacing the drilling fluids along the borehole with greater efficiency. If the drilling fluid is effectively gelled, it acts like a solid and can therefore respond with great sensitivity to pressure changes due to volume changes occurring near the drill bit. During the transition period from the non-gelled to the fully-gelled state pressure changes will increase. The drilling fluid must actually be allowed to gel. That means that the drill must not be operating, the drill string must not be moving, and the drilling fluid must not be being pumped along the borehole. Therefore, the method of determining fluid flow into or out of a borehole can be characterized by the following steps:

• to determine the yield stress and gelation period of the drilling fluid;

• to stop drilling, rotation and pumping, and, measuring the downhole differential pressure between two points spaced along the longitudinal axial orientation of the borehole;

• to determine the fluid flow, knowing the yield stress and observing changes in differential pressure during the gelation period.

In this method, the following apparatuses are used: a bottom hole assembly for drilling a borehole; a differential pressure monitor to measure the differential pressure of fluid in the borehole; and means for communicating the output of the differential pressure monitor to the surface.

A differential pressure monitor has two individual pressure sensors located on the exterior of the bottom hole assembly and suitably spaced at a distance about 30 cm.

The data gathered by the pressure monitor is best recorded for subsequent use. Rather than transmit the data directly up the string and to some suitable ground surface equipment, it is most preferably stored within the bottom hole assembly. It may then either be utilised there, or sent up to the surface.

Ex.3 Define a part of speech and translate the words.

Borehole, desirable, differential, data, preferably, assembly, surface, pressure,

subsequent, measure, axial, efflux, yield, continue, transmit, thyrotrophic,

certain, between, gelled, efficiently, therefore, inform, occurring, sensitivity, equipment, itself, interface, surprisingly.

Ex.4 Find synonyms among the following words.

Desirable, raise, outer, apparatus, fluid, certain, to continue, contact, effectiveness, to behave, data, to utilize, really, because of, to use, isolated, liquid, information, communicate, sure, exterior, efficiency, increase, device, pleasant, individual, actually, due to, to go on, to act.

Ex.5 Answer the questions to the text.

1. What is desirable to know when drilling a borehole for a well? 2. How can data about the influx or efflux of fluid be gained? 3. When should observation of pressure be carried out? 4. What is the reason to stop operating the drilling pump? 5. What is a drilling fluid? 6.Why is it important that the drilling fluid must be allowed to gel? 7.How can you characterize the method of determining fluid flow into or out of a borehole? 8.What apparatuses are needed for this method? 9.How does a differential pressure monitor work?

Ex.6 Make a sentence up of two parts.

It is desirable to be informed	observing the pressure within the borehole.
Data may then either be utilised there,	when fluid is passing through the walls of the borehole between the borehole itself and the formation.
data about the influx or efflux of fluid can be gained by	located on the exterior of the bottom hole assembly and suitably spaced at a distance about 30 cm.
A gelled fluid can transmit the force created by moving fluids	displacing the drilling fluids along the borehole with greater efficiency.
the drilling fluid is thyrotrophic like a non-drip paint,	or sent up to the surface.
A differential pressure monitor has two individual pressure sensors	and when not disturbed it will form a gel.

Ex.7 Use the right words in the sentences.

Influx, fully-gelled, steam, subsequent, acids, relevant, non-gelled, water, observation, the Christmas tree, in order to, efflux.

1. In certain circumstances data about the … or … of fluid can be gained by observing the pressure within the borehole.

2. This … should be carried out when the drill is still and the drilling fluid is not being pumped.

3. During the transition period from the … to the … state pressure changes will increase.

4. The data gathered by the pressure monitor is best recorded for … use.

5. The determination of the … fluid flow involves a number of factors.

6. … promote the gelation of the drilling fluid, all motion of the bottom hole assembly is stopped,

7. Also, secondary wells may be used to pump …, …, … or various gas mixtures into the reservoir to raise or maintain the reservoir pressure.

8. If the underground pressure in the oil reservoir is sufficient to force the oil to the surface, a complex arrangement of valves - … - is placed which connects the well to a pipeline network for storage and processing.

Ex.8 Discuss the following items in pairs. Try to clarify the specialist terms.

• Observation of fluid or gas influx;

• Gelation of a drilling fluid;

• Apparatuses for determining fluid flow into or out of a borehole;

Ex.9 Translate the following sentences from Russian into English.

1.Приток жидкости и газа к скважине обусловлен энергией и силами, действующими в нефтяных и газовых залежах. 2. Пластовая энергия зависит от пластового давления и общего объема всей системы нефтяной или газовой залежи и окружающей ее водяной зоны. 3. Нефтяные залежи постоянно пополняются водой из поверхностных источников в количествах равных количеству отбираемой нефти.4. Способ эксплуатации скважин, при котором подъем нефти или смеси нефти и газа на поверхность осуществляется за счет природной энергии, называется фонтанным. 5. Методы добычи альтернативного газа требуют использования особых технологий, где ключевым фактором является вода. 6. Часть воды, под давлением вводимой в скважину, выкачивают назад, когда начинается разработка. 7. Метан образуется в угольных пластах, которые либо залегают слишком глубоко, либо газ в них слишком низкого качества.

Ex.10 Retell text “Fluid or gas influx”.