Co-ordination of In-Seam Drilling Research

In-seam drilling technology and priorities for its application have changed considerably since 1993 when the scoping study into in-seam drilling was conducted. Technological advances have mainly been due to the changing attitude in the industry to in-seam drilling and its role in defining whether mining can be conducted. The main technological developments to date have been made by the mine operators and contractors with assistance from their suppliers, to solve their problems in the short term. Drilling is still mainly of shorter holes of the across panel drainage type with some longer holes for flanking development drives. Long exploration holes are not yet being applied to the limits of the available technology.

ACARP funded research has resulted in prototypes which have either been completed or will be completed over the next year and which should take in-seam drilling technology into the next generation. The continuing ACARP support of the project, Coordination of In-seam Drilling Research has facilitated the technological advances through promotion of communication amongst all players and through the monitoring of the research projects. Although the appointment of an ACARP in-seam drilling research coordinator has been extended beyond the number of years initially envisaged, the problems identified and refinements arising from a maturing in-seam drilling industry have reinforced the need for the continuing facilitation of communication amongst all players and its extension in 1999 and 2000 to cover gas and outbursts.

In-seam drilling has been applied more to defining hazard free coal during the year than in previous years. This is a major role for in-seam drilling. In the Western Coalfield, Newcastle and Oaky Creek area of Central Queensland, in-seam drilling has been conducted to prove that planned development will not intersect old workings (see reports on operators' meetings). This type of drilling requires safety precautions against the intersection of water filled old workings. At Kenmare Colliery, in-seam drilling has been used to provide detailed grades across faults to facilitate the passage of the longwall.

In Queensland, it has been realised that lower gas contents do not preclude the need for in-seam drilling. Higher permeability coal produces high rib emissions which can exceed permitted CH4 levels in the intake airways. Rib gas capture holes have been necessary. The Queensland coals also have higher gas emission rates according to Ray Williams of Geogas. This increases the potential for outbursts at lower gas contents than for NSW coal. Kenmare and North Goonyella collieries have demonstrated that the complexity of structural disturbance exceeds that which can be accurately assessed by surface drilling. Both mines have intersected structures which have not been predicted by closely spaced surface drilling and have applied in-seam drilling as a detailed exploration tool. The new generation Queensland mines could need more in-seam drilling than originally anticipated. To reduce the risks of gas related hazards and their potential for fatalities, it is important for the new mines to benefit from the knowledge and experience of other industry members. Continuation of this project will provide this opportunity.

Australian in-seam drilling expertise has been recognised during the year by the purchase of Australian drilling and survey equipment plus Australian drilling expertise by China and by South Africa. Australian drilling contractors, AMT Drilling and Valley Longwall Drilling conducted demonstration drilling and trained local personnel in China where difficult drilling conditions and poor safety exist. AMT Drilling trained South African drillers in guided drilling techniques and the use of the AMT Mecca system.

The NSW Department of Mineral Resources has adopted a more proactive approach to drilling. A committee was established under the chairmanship of Les Gardner to draft a set of guidelines for the preparation of drilling and drainage management plans. The committee is made up of representatives from the Department, industry, a drilling contractor and J. Hanes. The guidelines will allow each mine manager to develop individual systems for his mine, but quality and compliance will be required.

The ACARP funded research projects have had mixed success during the year. Some projects have made progress while others have been at a standstill for want of mine support. Others will grind to a halt unless host mines for underground trials come forward. The report details the project's progress.