Application of Well Log Analysis to Assess the Petrophysical Parameters of the Early Eocene Sui Main Limestone (SML) in Kharnhak-1 Well, Middle Indus Basin, Pakistan

The petrophysical analysis of the early Eocene Sui Main Limestone (SML) has been conducted inKharnhak-1 well for the prospect of the hydrocarbon exploration of the Khairpur-Jacobabad High,Middle Indus Basin, Pakistan. The petrophysical analysis of SML is carried out on the basis of welllogs including gamma ray, spontaneous potential, resistivity, neutron, and density logs. Theseanalyses lead to interpreting the vertical distribution of porosity and permeability in order to measurethe reservoir potential of the SML. The Archie equation was used to assess the petrophysicalcharacteristics. The SML has good porosity and poor permeability with positive correlationcoefficient between the two parameters. The average volume of shale is 18%. The log signature ofSML shows dominance of carbonates (limestone). The reservoir quality of the SML in Kharnhak-1well is such that it is 77% water saturated. The porosity (x) varies inversely with formation resistivityfactor (F) and compressional wave velocity (Vp). However, F and Vp are directly related with eachother. Thus, the electric and elastic properties of the carbonate rocks can be influenced by postdepositionalalterations, which include porosity enhancement and reduction processes respectively.

Keywords:

Petrophysical Analysis , Aui Main Limestone , Well Logs , Archie Equation , Reservoir Quality