Publication Name: PESA Journal No. 26
Authors: Christine West and PH Quah
Publication Volume: 26
Date Published: December 1998
Number of Pages: 7
Reference Type: Journal Article
Abstract:
An unexpected marked decrease in gas flow test rates afterfracture stimulation in well D14STL1x, Hanoi Trough,
Vietnam, compared to pre-fracturing production testing
rates, was investigated using reservoir geochemistry
techniques. Condensate samples taken before and after
fracture stimulation were analysed by whole oil gas
chromatography-mass spectrometry (GC-MS) and aromatic
GC-MS.
Geochemical data indicated that the post-fracturing samples
were not closely related to any of the pre-fracturing
production test samples, and furthermore suggested that
there was entry of terrestrial hydrocarbons into the well bore,
increasing in abundance with time, after fracture
stimulation.
Tt is believed that the composition of post-fracturing
condensate samples was changed due to seepage of
terrestrial coal gas derived from unintended out-of-zone
fracture propagation into underlying, non-reservoir, coaly
shales and siltstones.