Angular unconformity traps

1. The seas again invaded the area and a layer of chalk was deposited on the angular unconformity. This would become the cap rock of the East Texas field.

2. The sandstone was buried beneath the subsurface as it became covered by a layer of sediments from the sea.

3. Later, the Sabine Uplift, a geological event along the Texas-Louisiana border, arched up and exposed the Woodbine sandstone above the surface of the sea.

4. Approximately 100 million years ago, East Texas was covered by shallow ocean. The Woodbine sandstone was deposited during this geological era. This would become the formation rock of the East Texas field.

5. The top of the arch of the Woodbine sandstone was eroded and an angular unconformity was created.

Eventually, petroleum migrated from its source in the Eagle Ford shale along the Woodbine sandstone and became trapped by the layer of Austin chalk, accumulating into a reservoir of some five billion barrels of oil.

Task 5. Speak on «The geology of petroleum traps».

Задание 5. Перескажите текст «The geology of petroleum traps».

Практическое занятие 19

Geological Consulting to the Oil and Gas Industry

Геологическое консультирование нефтегазовой промышленности

consultant консультант

prospects поиски, разведка

teamed up with объединяться, работать сообща

concession концессионный договор

tectonic setting тектоническое положение

acreage площадь земли в акрах

dry hole непродуктивная скважина

farm-in opportunities возможность получить разрешение на поиск нефти и газа

licensed blocks земля, на которую имеется разрешение для разведки

risk assessment оценка риска

stochastic calculation вероятностные подсчеты

cumulative reserves подсчет совокупного количества нефти, добытой из скважины на определенную дату

ultimate endowment подсчет общего количества нефти, добытой из скважины за все время ее эксплуатации

depletion истощение скважины

risky venture рискованное вложение денег

cautious надежный

Task 1. Read an e-mail written by a consultant petroleum geologist, Paul Selby, to the manager of the Exploration Division of a large oil and gas company in Qatar, Adel Al-Jalawi. What is the purpose of the e-mail?

Задание 1. Прочитайте электронное письмо геолога-консультанта Пола Селби руководителю отдела разведки месторождений одной из больших нефтегазовых компаний в Катаре Адель-аль-Жалави. Какова цель писма?

Dear Mr Al-Jalawi

I contacted you just over two years ago and you were good enough to allow me time to show you some data we had assembled on prospects in the Ngosso and Iroko license areas off the coast of Cameroon. In the end, you decided not to invest in this area, but as you will know, it has become apparent since then that there are some excellent prospects here. A number of other companies have drilled wildcats and over a dozen wells are now producing. We have continued to do research offshore of Cameroon, as well as of Gabon and Equitorial Guinea, and we have now teamed up with a seismic company, Exploration Geosciences. If you would be interested in seeing our findings on more than 20 prospects in offshore West Africa, I would be delighted to make an appointment to present and discuss them in greater depth. I have attached an updated list of our main petroleum geology services. I look forward to hearing from you.

Yours sincerely,

Paul Selby

Managing Director, Selby Geo-Prospects Ltd

Task 2. Read an extract from the attachment sent by Paul Selby. Answer the questions which topic is relevant if a company would like…:

Задание 2. Прочитайте отрывок из приложения, которое прикрепил Пол Селби к своему письму, и ответьте на вопросы:

Which topic is relevant if a company would like…

1. to have more information about areas which are already being drilled?

2. to know how much oil and gas is present in a possible oil and gas field?

3. to have detailed geological information about an oil and gas field?

These are the main services offered by Selby Geo-Prospects.

Please contact us if there are any geological or geophysical services you would like us to supply.

Regional evaluations

Countries, regions, basins, concessions. Analysis of tectonic setting, structural evolution, stratigraphy, geochemistry, petroleum systems, exploration history, reserves and future potential.

Open-acreage assessment

Exploration history, drilling results, discoveries, dry holes, reservoirs, seals, traps, source rocks, timing of migration and remaining potential.