Online Journal for E&P Geoscientists

Rahaman, Mafizar ^*1; Ebrahim, Maitham ¹; Al Zuabi, Yousef ¹; Gandhi, Dipankar ¹
(1) Exploration Group, Kuwait Oil Company, Ahmadi, Kuwait.

Minagish Feld was discovered in 1959, where the Minagish Oolite reservoir of Lower Cretaceous age is the prolific producer of hydrocarbon and it accounts for more than 80% oil production of the field. This reservoir is well developed in Southern Kuwait oil fields and its porosity varies from 20% to 28%. Few of the wells drilled in the field show an additional reservoir developed below the main Minagish Oolite reservoir, called as Lower Minagish reservoir. The thickness of the reservoir varies from 150 to 200 ft and its porosity varies from 15 to 20%.Here most of the wells were drilled targeting main Minagish Oolite reservoir, however few of the wells are recently deepened to evaluate the oil potential of Lower Minagish reservoir. Production testing result shows Oil production rate varies from 400 to 4300 BOPD with the Oil API varies from 20.5 to 31deg, which is significantly lower API of main Minagish Oil. Since the extension of the reservoir is limited and well productivity is highly variable due to rapid lateral variation of porosity and permeability a good understanding of the reservoir was essential. The key challenge is to improve the description of reservoir and its internal heterogeneity using 3-D Seismic along with Geological and Petrophysical data.

In the multidisciplinary integrated study Geophysical, Geophysical and Petrophysical data were combined through deterministic seismic inversion technique and generated Acoustic Impedance volume for Lower Minagish reservoirs. In the inversion process, low frequency component (0 to 10 Hz) has been utilized from well data and high frequency component (10 to 60 Hz) has been obtained from seismic data. Relation between porosity and Acoustic Impedance was established using well data and applied in transforming impedance into Porosity volume.

The study has brought out an area of excellent porosity development near the structural highest part of the field. It has provided a better understanding of internal reservoir heterogeneity, facies variation within the reservoir. The study has provided a strong base in planning and placement of horizontal well targeting Lower Minagish reservoir.