Reconnaissance is an early stage of exploration to understand the general condition of surface geology in particular area. In further, reconnaissance is aimed to understand the existence and spread of coal, to identify the properties of the coal, to localize the prospect area, and build the reference for future exploration.
This early study consists of pre-field and field observation.
Step by step coal exploration
PT. Geoservices provides various exploration services as well as coal exploration. It is essential for your first step to perform exploration work prior to mining. Exploration is the first stage to provide sufficient and proper geology data to evaluate whether or not a coal reserve is potentially profit to be exploited.
1. Geological Reconnaissance Investigation
Pre-field observation
Pre field observation is also known as desk and literature study. Pre field observation identifies the location according literature, books, and references. This activity may generate a work map of a targeted location (scale 1:50,000).
Field observation
After the completion of desk study, field geological observation is carried out. The geological observation will be performed in the areas where outcrops and possible structural geology is exist (according to findings obtained during desk study), such as in the rivers and its nearby surrounding area.
The position of traverse, observation, and sampling points will be established by handheld GPS. The geological and traverse data will be then plotted on a work map and every geological observation location will be marked with code/certain number. The outcrop and structural geology photos is also taken generally.
The outcome of this investigation is observation map (scale 1:50,000), geological map and section (scale 1:50,000), coal resources map (scale 1:50,000), coal outcrop profile (scale 1:20), coal outcrop documentation, geological database, coal quality evaluation, calculation of coal resources, conclusion and recommendation.
2. Semi Detail Exploration
The objective of semi detail exploration is to provide detail geological data which enough and accurate regarding coal type and quality, coal resources, geological structure, and coal morphology. Scope of work of semi detail exploration is as followed:
● Geological Mapping, scale 1:5.000
● Topographical Mapping, scale 1:5.000
● Drilling (coring and open hole)
● Geophysical Logging
● Coal Sampling
● Coal Sample Analysis
The result of this exploration is 2 and 3 dimension geological model, isopach and isoquality map, and coal reserve map.
Detail exploration is the final step of exploration. The purpose of detail exploration is to provide more detail geological data than that provided by previous investigation and semi detail exploration.
The scope of this last step of exploration is:
● Geological Mapping, scale 1:1.000
● Topographical Mapping, scale 1:1.000
● Drilling (coring, open hole) short distance
● Geophysical Logging
● Coal Sampling and Analysis
● Coal Sampling and Geotechnical Analysis
● Hidrogeology Data Observation
After performing detail exploration work, detail calculation of coal resources and mineable reserve, stripping ratio map, iso coal map, 2 and 3 dimension geological model of particular area can be obtained.

Feasibility study, AMDAL, and mine design
After completing the exploration work, a study on the coal reserve, and mining shall be carried out to assess the viability of the coal mining venture. An environment assessment to see the impact of activities on the physical and social environment shall be conducted to satisfy the AMDAL requirements to obtain the mining permit (IUP).
By the use of Mincom Minescape as well as Gemcom Supac, PT. Geoservices assists you in geological modeling, mine design, and planning.
3. Detail Exploration
Drilling Services
Commenced business in 1974, since then it has progressively developed over 3 decades. Until it now finds itself ranked as one of the leading slim hole drilling companies in Indonesia. During its history, the division has developed many kinds of drilling methods from diamond core, open hole drilling to large hole drilling.

Scope of Services
● Exploration drilling for minerals and coal
● Water well drilling
● Drilling for grouting
● Environmental drilling
● Site/Geotechnical investigation for civil worksmap, and coal reserve map.
PT GEOSERVICES