Unconventional gas and oil potential in Estonia

Sixth Seminar on Cooperation on the EIA Convention in the Baltic

Sea Region

September 21, 2012 Tallinn, Estonia

Tarmo All

Mineral Resources Department

What is the shale gas? ● type of unconventional gas most discussed and

contentious currently (Philippe & Partners, Final report - 8 November 2011)

● other unconventional sources of natural gas include coalbed methane, tight sandstones, and methane hydrates

● shale gas is a natural gas produced from shale

What is the shale? ● a fine-grained, clastic sedimentary rock ● the process in the rock cycle which forms shale is –

compaction ● the process by which a sediment progressively loses

its porosity due to the effects of loading

How dose the gas appear in shale? ● shale that host economic quantities of gas is rich in

organic material (0.5% to 25%) ● black shale – more than one percent carbonaceous

material ● gas containing shale are usually petroleum source

rocks in the thermogenic gas window, where high heat and pressure have converted petroleum to natural gas

HC generation

Is it a new resource? ● shale gas has been produced for years from shales

with natural fractures ● the shale gas boom in recent years has been due to

improvment in technology - hydraulic fracturing ● compared to tight gas and coal bed methane,

relatively less experience exists in Europe for shale formations as a source of natural gas

● In Estonia there are two kinds of shale: kukersite (kerogen) and Dictyonema argillite (kerogenous claystone)

Shale formations in Estonia

Oil shale (kukersite) ● an important resource for the national economy

● country generates 90% of its power from this source ● lies near the surface and dips to the south, so that

deposits are found at depths from 7 to 170 metres ● more than 40% organic content

Oil shale in Estonia

● the Estonian oil shale deposits covers about 3000 km²

● approximately 425 km² have been mined ● the reserve of usable oil shale is about 1 billion

tonnes ● the calorific value of the usable oil shale is 1900-

2600 kcal(8-11 MJ/kg)

Oil shale gas ● oil shale gas is a synthetic gas mixture (syngas)

produced by oil shale pyrolysis ● shale is heated until its kerogen decomposes into

vapours of a petroleum-like condensable shale oil, non-condensable combustible oil shale gas, and spent shale - a solid residue

● oil shale gas occurs as a by-product of shale oil production

● it may be used for heating the pyrolysis process

Dictyonema argillite

● Dictyonema argillite (also known as Dictyonema shale) is a brown lithified claystone belonging to the formation of black shales

● it occurs in most of northern Estonia on an area of about 11,000 km²

● the thickness of the Dictyonema argillite layer varies from 0.5 metres to 8 metres and lays at a depth of 10 to 90 metres.

Dictyonema argillite (shale) ● reserves of Dictyonema argillite are estimated

approximately to 70 billion tonnes. ● its quality is poor as a source for the energy

production (heating value 5–8 MJ/kg, Fischer Assay oil yield 3–5%)

● the organic content varies from 10 to 20%

Gas explorations on Alumshale in Sweden

● there are on going explorations for unconventional gas sources – shallow biogenic gas deposits from black shale

● the gas has formed by the bacteria feeding from the organic content of the shale and converting part of the organic material in the shale into methane

Scale gas exploration in Estonia 1

● in Estonia no studies on Dictyonema argillite or Kukersite as the possible source for biogenic gas have been accomplished

● recently some scientific studies on organic rich rocks as possible source for biogenic gas has been started by Tallinn Technical University

● the first results are expected in 2013-2014

Scale gas exploration in Estonia 2

● there is one application for geological exploration licence do study the shallow organic rich formations as possible source for commercial biogas production

● Ministry of the Environment is proceeding the application

● most likely the EIA is not needed

The prospectivity of biogenic gas from the organic rich strata (dictyonema shale)

● very preliminary knowledge ● no practical solutions or experiences ● unknown environmental impact ● if any resources will be proved then most likely

application would be the small flexible installation (like generators of scalable output 50-200 kWh)

THANK YOU

FOR YOUR ATTENTION