TITLE:
A Method of Calculating Saturation for Tight Sandstone Reservoirs: A Case of Tight Sandstone Reservoir in Dabei Area of Kuqa Depression in Tarim Basin of NW China
AUTHORS:
Jun Tang, Yi Xin, Deyang Cai, Chengguang Zhang
KEYWORDS:
Tight Sandstone, Fracture, Saturation, Conductive Pore Water
JOURNAL NAME:
Open Journal of Yangtze Oil and Gas,
Vol.3 No.1,
January
31,
2018
ABSTRACT: The tight sand reservoir in Dabei Area has been the
main block of exploration and development of natural gas inTarimBasin. Because of low
porosity and fracture development, there exist errors in calculation of
reservoir saturation. According to micro-resistivity image logging and acoustic
full-wave logging, the reservoir fractural effectiveness is quantitatively
evaluated; the result indicates that the reservoir with Stoneley wave permeability is greater than 0.2 × 10-3μm2; the
reservoir connection is good. If the
FVPA is greater than 0.055%; the
fractures are developed. A new matrix saturation model is established based on
the conductive pore water in consideration of the influence of low porosity.
After modeling and analyzing the effect of porosity and its occurrence on the
cementation index, the method for saturation calculation in Kuqa Area is established:
the newly established dual porosity model is for fracture developed reservoirs,
and the model based on the conductive pore water is for fracture less-developed
reservoirs. By comparing the results of saturation in mercury injection
experiment from coring section, precision of the calculation method is proven.