asked the Minister for Energy the likelihood of a commercial oil find in Irish waters within the next five years; and if he will make a statement on the matter.
21.
Written Answers. - Offshore Oil and Gas Finds.
13.
asked the Minister for Energy the approximate life span of the natural gas supply; if other sources of supply are likely within Irish waters or in Ireland; and if he will make a statement on the matter.
I propose to take Questions Nos. 13 and 21 together. The recoverable reserves of gas in the Kinsale Head gas field, which I presume is what Deputy Mitchell is referring to are, on the basis of current estimates, expected to last at least until the end of the century. Obviously, however, the life expectancy of the field will ultimately be determined by the rate at which the gas is actually depleted.
The Kinsale Head gas field is of course our only commercially producing field at the moment and in considering questions about the prospects of further commercial oil or gas finds offshore Ireland, one must look at the geological and engineering aspects of hydrocarbon exploration and development in our offshore. Exploration here is still at a relatively early stage and the major sedimentary basins are only partially explored.
Nevertheless, we have had numerous indications of commercial hydrocarbon potential even though many of the wells drilled did not test the deeper geological horizons which are now considered to be of the greatest interest. Furthermore, the bulk of our wells have been drilled in the Celtic Sea and Porcupine Basins. Apart from these, only a minimal amount of exploration has taken place in the Donegal Basin, the Erris Trough, the Slyne Trough and indeed in the Kish Bank Basin where the first exploration well to be drilled since 1979 has just been spudded. From the engineering side too, our offshore presents a variable picture. Water depts vary from 200 to 300 feet off the south and east coasts to 600 to 1,000 feet or more off the west coast. Accordingly it will not be possible to determine the commerciality or otherwise of oil or gas discoveries on the basis of field size alone, without taking water depths and proximity to shore into consideration.
It is not possible, therefore, to predict with any degree of accuracy the likelihood of finding commercial oil or gas fields either in Ireland or offshore Ireland until exploratory wells drilled have actually proved the presence of movable hydrocarbon accumulations which on appraisal and delineation are proven to be capable of sustaining production commercially. The results of seismic work carried out and of the wells drilled to date have provided for the oil exploration companies and for my Department a deeper insight into the geology of our offshore basins than hitherto obtained and certainly show that there is considerable potential in the Irish sedimentary basins for future commercial discoveries and the number of significant flows and shows of hydrocarbons from the discoveries made to date are extremely encouraging. Nonetheless, it is not possible to say as yet whether any or all of the discoveries made so far will ultimately lead to commercial developments. The companies concerned are continuing, in consultation with my Department, their assessments of some discoveries and of the areas in the vicinity of those discoveries with a view to establishing whether or not recoverable reserves of sufficient magnitude are in-place to support commercial production.
Given the increased level of drilling in our offshore this year, I believe, along with the oil companies who are going to drill exploration wells for the purpose of finding oil or gas, that new discoveries could be made. However, the timescale for a commercial development in relation to such future discoveries would, in the first instance, depend on when the discoveries are made and proved up.