Present Gas Reserve Estimation Using Wireline Logging Data of Habiganj Gas Field, Bangladesh

Abstract

Habiganj Gas Field (HGF) is one of the most producing and promising gas field in Bangladesh which is ranked as second largest gas field in aspects of Gas Initially In Place (GIIP). It formed by a north south elongated anticline which lies in the northernmost end of the 130km long Baramura anticline from Tripura (India) in the south. This paper shows the present gas reserve estimation with a view of four gas producing wells (i.e. HBJ-7, HBJ-9, HBJ-10, and HBJ-11) in account of upper gas sand has been access via the investigation of lithology, wire line logging data and production data are used as parameter for volumetric method. The average water and gas saturation of the reservoir has also been determined by Archie equation. From the previous analysis with logging data of HGF, it was found that the Gas Water Contact (GWC) was at 1458m and at present it is at about 1415m. The upper gas sand lies at a depth of 1320m below the surface and has a maximum gross pay 230m thick. The gas sand shows average porosity 30% (calculated from the combination of neutron and density porosity logs) and average permeability in the range of 2-4 Darcy's which indicates an excellent quality reservoir. The water saturation of Habiganj gas sand layer is considered for the depth range of 1330m to 1510m with 5m interval in-deed. Thereafter, water saturation and gas saturation of those wells (HBJ-7, HBJ-9, HBJ-10 and HBJ-11) are 27% and 73%, 29% and 71%, 15% and 85%, and 19% and 81% respectively. The gas formation volume factor (B g ) is estimated at about 0.0075 (rcf/scf) for the average 2053.13psi shut in pressure. From the above discussion it is found that the Gas Initially in Place by HBJ-7, HBJ-9, HBJ-10, and HBJ-11 wells are 5.35Tcf, 4.83Tcf, 5.71Tcf and 5.20Tcf respectively and the cumulative reserve for the HGF is 5.25Tcf while the recoverable reserve is 3.13Tcf. This study would be significant implications for reserve estimation and decision making in an effort to explore the present condition of gas reserve in HGF and the techniques described here can be used in other gas field as a base line for projections of gas reserve.

Petrophysical Reservoir Characterization of Habiganj Gas Field, Surma Basin, Bangladesh

“…However, no detailed research is done so far for reevaluation and reappraisal of this field. Few studies have been conducted on reserve re-estimation and characterization particularly on Habiganj Gas Field but those are based on few selected wells of the field where one reservoir zone had been considered (Rahman et al, 2017;Shofiqul and Nusrat, 2013). Thus, it is mandatory to do a research including all the wells of Habiganj gas field to detect all possible reservoir zones for a detailed reservoir scenario of the field.…”