1. Project Oriented Dissertation
On
FACIES CHARACTERIZATION OF CLASTIC
RESERVOIR OF LOWER GORUAND PARIWAR
FORMATIONS, JAISALMER BASIN ,RAJASTHAN, INDIA
At
KDMIPE,ONGC,DEHRADUN
Presented by:-
SAMIUR RAHMAN KHAN
Roll No.-10479SCoo3

2. Introduction
 Cores obtained while drilling (using a core-barrel), by virtue of
their size and continuous nature, permit a thorough geological
analysis over a chosen interval.
 The area under study lies in northwest part of Jaisalmer Basin,
Rajasthan
 This project work pertains to the study of only Mesozoic
section(Lower Cretaceous) in the subsurface as a number of
hydrocarbon occurrences have been reported in the area
especially in Pariwar and Goru formations.
Objective
This study is applied to understand detailed information about
the sedimentary rock type, mineralogy, texture, sedimentary
structures and the variation of rock property of Lower Cretaceous
Clastic section of Jaisalmer Basin ,Rajasthan.
The data generated thus was taken to interpret the subsurface
lithological variations, depositional environment and reservoir
characteristics

3. Geological setting
 Rajasthan basin is a peripheral fore-land basin & it is
a Category- I basin.
 Rajasthan basin possesses three important basins viz.,
Jaisalmer, Bikaner-Nagaur and Barmer, stretching over
an area of about 1,20,000 sq. km. These basins are bound in the east and south-east by
the Aravalli ranges and in the north-east by Delhi-Sargodha ridge. Towards the north and
north-west it merges in to the Indus shelf. The western and south-western limits are
marked by the Jacobabad High and Badin platform in Pakistan.
 Jaisalmer basin is the westernmost is separated from the Bikaner- Nagaur basin by the
Pokaran-Nachana high to the northwest and from the Barmer basin by the Barmer-
Devikot- Nachana high in the south.
 A pronounced NW-SE-trending regional
step-faulted Jaisalmer-Mari high zone,
marked by the Kanoi and Ramgarh faults
that traverse the centre of the basin and
divides it into the Shahgarh sub-basin, the
Miajalar sub-basin and the
Kishangarh sub-basin

4. Tectonics Zones Map of
Western Rajasthan Basin
(Source-www.dghindia.com)

5. Methodology adopted
1-Megascopic study
2-Petrography or Thin section study
3-X-ray diffraction
4-Scanning Electron Microscopy

6. DETAILS OF CONVENTIONAL CORES

7. Details of sample for various studies
Details of thin section DETAILS OF SAMPLE FOR X-RAY DIFFRACTION
DETAILS OF SAMPLE FOR SEM ANALYSIS

8. MEGASCOPIC STUDY OF CONVENTIONAL CORE-1(cc-1)Lower Goru Member
 Megascopically ,the core comprises dark grey ,hard and compact, fine to medium
grained, sub angular to sub-rounded , micaceous and calcareous sandstone ,
brachiopoda shell along with glauconite and dark color minerals .At some places it
is showing flaser bedding.
showing reaction with HCL10%
Flaser bedding

9. Petrography of conventional core-1
 Petrographically the sandstone consists of Quartz (60-
75%),Glauconite (10-20%) ,mica (up to 5%),opaque minerals like
pyrite(less than 5%),feldspar (upto3%),ferruginous clayey matrix (up
to 10%),and ferron calcite cement (up to5%).
 Petrographically these sandstones are lithic arenites

10. X-Ray Diffraction analysis of conventional core-1
X-Ray Diffraction analysis of clay fraction of the
core(Depth-1418.45m, 1426.40m) indicate the
presence of kaolinite 78.25% , 79.42% and illite
21.75% -,20.58%.

11. SEM analysis of conventional core-1
B
QO
Q
k
p
s

12. MEGASCOPIC STUDY OF CONVENTIONAL CORE-2(lower Goru Member)
 Megascopically the core comprises dirty white to grey ,hard and compact
,very fine grained/ siltstone, sub-angular to sub rounded, calcareous
sandstone with lot of dark minerals and micaceous with black to dark
grey fissile shale. Sandstone showing small scale cross-lamination.

13. Petrography of cc-2(Lower Goru Member)
 Petrogarphic study indicates sandstone are moderately sorted sub-
angular to sub-rounded quartz (50-70%), mica (5-10%),rock fragments
sideritic clay clasts (upto5%),clayey matrix up to 10%,ferron calcite
cements( 5-10%),with traces of feldspar ,glauconite and opaque minerals
along with authigenic kaolinite.
 Petrographically these sandstone are quartz wacke.

14. XRD ANALYSIS OF CC-2 (BULK SAMPLE ANALYSIS) Lowre Goru Member
Bulk sample analysis by X-Ray Diffraction of the core(Depth-1514.47m)
indicates dominance of quartz 73.7%, kaolinite 14.2% , siderite 7.1% ,
illite 4.2% and minor calcite.

15. X-Ray Diffraction analysis (clay fraction)
X-Ray Diffraction analysis of clay fraction of the core(Depth-
1514.47m,1513.42m, 1516.40m) indicate the presence of kaolinite
82.11% ,94.25%and69.74% and illite 17.89%,5.75% and 30.26%.

16. SEM analysis of conventional core-2
 Scanning Electron Microscope study of sandstone samples with
moderate to good intergranular porosity .The intergranular
porosity are occupied by authigenic kaolinite and patchy calcite
cement and quartz overgrowth.

17. MEGASCOPIC STUDY OF CONVENTIONAL CORE-4( Pariwar formation)
 Megascopically the core comprises dark grayish brown ,hard and
compact , fine to medium grained, sub-angular to sub rounded,
micaceous and sandstone with ferruginous cement. Effect of chemical
weathering.

18. Core Log
CC-1(lower Goru Member) CC-2(lower Goru Member) CC-3(lower Goru Member) CC-4(Pariwar Formation)

19. CONCLUSION
 Petrographically the sandstones of Lower Goru membe are
calcareous quartz arenites and quartz wacke.
 The lower Goru Member of Goru formation has been deposited in
an overall regressive phase with intermittent marine Incursions.
 Presence of glauconitic sandstones and shales are indicative of
shallow marine conditions.
 Ferruginous sandstone, grey shales with brachiopod shell, and
current bedding are suggestive of continental to parallic
environment.
 The Lower Goru Member could be either shallow water marine or
extensive alluvial plain eustarine deposits where both wind and
water had their role to play.
 The Pariwar Formation mostly comprised moderately sorted
sandstone having good reservoir characteristics

20. CONCLUSION(continued)
 Through Petrographic observations ,it is noted that the porosity
has been deteriorated due to occlusion of Ferron Calcite cement
as well as siderite in the intergranular spaces of sandstone .This
inturn reduces the permeability. In some instances Quartz
overgrowth is also noted which has adverse effect on
Petrophysical character of Reservoir.
 X-Ray Diffraction analysis of matrix of the sandstone revealed
the presence of Clay minerals like Kaolinite ,illite and smectite as
detrital clay .
 SEM studies has brought out intergranular porosity clearly seen
on the images ,however at places due to presence of framboidal
pyrite , Smectite and Illite along with altered mica and altered
feldspar the reservoir quality of sandstone is deteriorated

21. Thank You