Well drilling in the Philippines currently account for 66 % of the cost of a
steamfield development and 33 per cent of the total project cost. A key element which
directly influences the drilling cost is associated with the problems on
unrecoverable loss of circulation and collapsing formations which hindered drilling
progress. Considering its significant impact in the pricing of steam, and the need to
make the geothermal electricity price more competitive, geothermal operators in the
Philippines continue to search for innovations to test new technologies that would
speed up drilling operations. Recent drilling results indicate an emerging and better
performance that was previously subsumed to be unpredictable, based on a wide scatter
in the Cartesian plot of the total depth (TD) drilled versus duration.  


Considerations applied in well design, drilling practices and completion technology
in the Philippines are discussed in this paper. Downhole logging, to determine static
formation temperatures while drilling, aides in setting the production casing at
desired temperatures. Right-sizing of casing allows wellbore output optimization and,
thus reduces total well requirements for highly permeable reservoirs.
Hydro-fracturing, thermal fracturing and acidizing have been effective in improving
production and injection capacities of wells. Under-balanced drilling using aerated
mud and water in an under-pressured reservoir significantly improved drilling
performance and led to attainment of drilling targets and successful completion of
wells. The completion of >2500 meter well in less than 30 days had been achieved
through the  use of portable top drive equipment, high performance polycrystalline 
diamond bits (PCD), high temperature mud motors and implementation of improved
drilling practices.

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