Application of azimuth gamma in coal bed methane horizontal wells

Abstract:

As one of the well types for coal seam methane development， horizontal wells present difficulties for drilling， including safe landing， coalbed intersection rate， reservoir protection， anti-collapse and anti-sticking； and among them the coal seam intersection rate is an important index to improve gas productivity. With the continuous development of drilling technology and MWD tools， geological logging probes， short subs and geo-steering technology have also been applied in the drilling of coal bed methane horizontal wells. At present， gamma probes， particularly azimuth gamma probes， have found wide use in coal bed methane horizontal well drilling. Gamma probes can provide downhole geological parameters for the field decision-makers with their functions of lithological identification， formation correlation， and apparent formation dip calculation； thus， effectively serving the drilling. This paper describes the application of azimuth gamma probes in coal bed methane horizontal well drilling in the context of drilling of a coal bed methane horizontal well.