1 : TOTAL E&P, Technology Centre, CSTJF, Pau France 2 : ENSEGID - Bordeaux INP 3 : TOTAL E&P Qatar

Transcription

1 Stratigraphy and sedimentology of the middle Cenomanian Natih Formation in the Jabal Shams area (Jabal Akhdar, Sultanate of Oman): An outcrop analogue for reservoir heterogeneity in the Mishrif Formation of Al Khalij field (Qatar). Robinet, J. (1, 2), Razin, P. (2), Grélaud, C. (2), Peyre, M. (2), Caline, B (1), Boichard, R. (1), Poutier, A. (1), Pigeaud, T. (3), Fernagu, J.(3), Al Tamimi, F. (3) 1 : TOTAL E&P, Technology Centre, CSTJF, Pau France 2 : ENSEGID - Bordeaux INP 3 : TOTAL E&P Qatar In the eastern Arabian Plate, the Middle Cenomanian series correspond to a very extensive inner carbonate platform system, which developed between the Arabian Shield in the southeast and the Tethys margin in the north. The assumed large extension of the platform and the regional stratigraphic correlation led to study the Middle Cenomanian Sequence II of the Natih Formation (Natih D and C members) in Oman as a field analogue of the lower part of the upper Mishrif Formation in the Al Khalij field in Qatar. The thorough mapping of more than 20 fifth-order sequences over continuously-exposed outcrops in the Jabal Shams area (SW Jabal Akhdar, Sultanate of Oman) allows the physical correlations of about 100 field-sections calibrated by thin-section analysis. This resulted in a robust, high-resolution, almost 3D, sequence stratigraphic model which records the evolution of the depositional profile and facies distribution of the carbonate system through time. This study allows to define the main factors controlling this evolution, to quantify the geometries and to understand the distribution of geobodies, which show the best reservoir potential. The lower part of the Sequence (Natih D Mb., 45 m-thick) corresponds to homogenous, tabular aggradation of shallow-marine, muddy carbonate platform deposits during a period of an overall increase in the rate of accommodation creation. The upper part of the sequence (Natih C Mb., 15 m- thick) is characterized by more complex stratigraphic geometries, displaying a wide range of dip angles (0 to 30 ) and rapid lateral facies variations. This complexity is the result of the differential aggradation of shallow carbonate platform deposits during the period of maximum increase of accommodation rate, leading to the development of localized depressions (less than 10 m deep) on the platform top. The resulting low-angle dip of the depositional profile had a major influence on the

2 hydrodynamic conditions of the system, as revealed by the progressive development of high-energy grainstone facies on the shallow highs. Improved marine conditions are inferred to have been responsible for palaeoecological change, as shown by the development of rudists and an increase in carbonate production at this time. This inversion of the ratio between accommodation and sedimentation rates resulted in the filling of the small depressions, characterized by a succession of prograding systems tracks of variable angles (5 to 15 ) displaying rapid lateral facies changes. Coarse, high-angle (up to 30 ) rudist rudstone sand-waves of high permeability potential developed locally and repeatedly within this regressive fill unit. The geometries and distribution of significant stratigraphic heterogeneity observed within the overall tabular ( layer cake ) Middle Cenomanian Sequence II of the Natih Formation work provides a well constrained field analogue for the time-equivalent Natih and Mishrif reservoirs in the Middle East.

3 Paper No.1493 Stratigraphy and sedimentology of the middle Cenomanian Natih Formation in the Jabal Shams area (Jabal Akhdar, Sultanate of Oman): An outcrop analogue for reservoir heterogeneity in the Mishrif Formation of Al Khalij field (Qatar). Jérémy ROBINET 1&2, Philippe RAZIN 2,Carine GRELAUD 2, Maxime PEYRE 2, Bruno CALINE 1, Robert BOICHARD 1, Antoine POUTIER 1, Thierry PIGEAUD 3, Fahad AL TAMINI 3, Noureddine BOUNOUA 4 & Tarek GAGIGI 4 1 TOTAL E&P Technology Centre, France 2 ENSEGID, France 3 TOTAL E&P, Qatar 4 QATAR PETROLEUM, Qatar Session 37: Carbonate Stratigraphy and Sedimentology December 9 th, :30 09:00

4 OBJECTIVES Slide 2 Al Khalij Field Studied area Characterization of the reservoir heterogeneities of the Upper Mishrif Formation in the Al Khalij Field (Qatar) Geological constrains on the distribution, extension and geometry of the different facies (Konert et al., 2001) 105 Ma (Albian) Laurasia Albian Cenomanian : Very large platform on the Neo Tethys margin Gondwana Analogies between the Mishrif Formation in Qatar and the Natih Formation in Oman Blakey, 2011 paper n Outcrop study of the Natih Formation in Oman Robinet et al.

5 Cretaceous carbonate platform in Oman Natih E Natih D Natih C Natih B & A (undifferentiated) SI 30 m Upper Mishrif Natih Fm. 30 m Sequence SII Sequence SIII STRATIGRAPHY Slide 3 Oman outcrops Al Khalij Field ARUMA Gp. Fiqa eq. Laffan Shales WASIA Gp Seq. III Seq. II SB7 bis SB 7bis? KHAMAH / Seq. I THAMAMAH SB 7 Gp. Nahr Umr Fm. SB6 Lower Mishrif SB 6 SAHTAN Gp. (Razin et al., 2005) Viéban et al., 2006

6 N FIELD WORK LOCATION Slide 4 Detailed study in the Jabal Shams area 100 km Sultanate of Oman (Özcan et al., 2015) N Detailed study Jabal Shams Gulf of Oman Jabal Akhdar Reference sedimentological section Al Hamra Al Hoota Top of sequence II Base of sequence II Faults Paper # Paper Title Presenter Name

7 25 m TRANSECTS OF CORRELATION & FACIES DISTRIBUTION B Slide 5 Large scale transect SW NE B S6 S5 S4 S3 Vertical exaggeration : x 250! S2 S1 10 km

8 25 m 15 m Detail transect TRANSECTS OF CORRELATION & FACIES DISTRIBUTION B Slide 6 S6 2 km SW Vertical exaggeration : x 50! NE B S6 S5 S4 S3 Large scale transect S2 S1 10 km

9 Paper # Paper Title Presenter Name FINE-GRAINED MUD DOMINATED FACIES Muddy deposits type 1 Muddy deposits type 2 Slide 7

10 COARSE-GRAINED RUDISTS RICH DEPOSISTS Slide 8 paper n Outcrop study of the Natih Formation in Oman Robinet et al.

11 5m Vertical exageration : x 50

12 15 m NATIH C SW Slide 10 8 km NE Muddy deposits type 1 (MUD 1) Bioclastic grainstone Muddy deposits type 2 (MUD 2) Shallower Deeper Paper # Paper Title Presenter Name 2 mm

13 25 m TRANSECTS OF CORRELATION & GEOMETRIES B Slide 11 SW NE B S6 Sub-horizontal profiles S5 S4 S3 S2 S1 10 km

14 25 m 15 m Medium to very high-angle profiles TRANSECTS OF CORRELATION & GEOMETRIES B Slide 12 SW S6 2 km Vertical exaggeration : x 50! NE B S6 Medium to very high-angle profiles S5 S4 S3 Sub-horizontal profiles S2 S1 10 km

15 B 2. MEDIUM TO VERY HIGH-ANGLE DEPOSITIONAL SYSTEM Slide 13 Sandwaves MUD 1 Rudists MUD 2 MUD 1 Rudists MUD 2 1. SUB-HORIZONTAL DEPOSITIONAL SYSTEM MUD 1 Rudists MUD 2??

16 SEQUENCE II (60 m) B STACKING PATTERNS (3 rd order) Slide 14 Pure carbonate system Higher rate of accommodation SLIDE TITLE HERE Top Seq. II Top Seq. II Argillaceous carbonate system Low rate of accommodation Top Seq. I Top Seq. I Paper # Paper Title Presenter Name

17 3 m STACKING PATTERNS (High frequency) Slide 15 Shallow-up sequence Rudists Coarsening-up 10 m Burrows MUD 2 Shallowing-up Deepening-up sequence Rudists Coarsening-up x m MUD 1 Deepening-up

18 SW STRATIGRAPHIC EVOLUTION Slide 16 NE 15 m 1 km Paper # Paper Title Presenter Name Not to scale

19 SW 1. Homogenous aggradation Slide 17 NE 1 km 15 m Paper # Paper Title Presenter Name Not to scale

20 SW 1. Homogenous aggradation Slide 18 NE 1 km 15 m Paper # Paper Title Presenter Name Not to scale

21 SW 2. Differential aggradation Slide 19 NE 1 km 15 m Shoal Swell Paper # Paper Title Presenter Name Not to scale

22 SW 2. Differential aggradation Slide 20 NE 1 km 15 m Shoal Swell Paper # Paper Title Presenter Name Not to scale

23 SW 3. Maximum of accommodation Slide 21 NE 15 m 1 km Shoal Swell Paper # Paper Title Presenter Name Not to scale

24 SW 4. Swell filling : Progradation Slide 22 NE 15 m 1 km Paper # Paper Title Presenter Name Not to scale

25 SW 4. Swell filling : Progradation Slide 23 NE 15 m 1 km Paper # Paper Title Presenter Name Not to scale

26 SW 4. Swell filling : Development of rudists sand waves Slide 24 NE 15 m 1 km Rudists sand waves Paper # Paper Title Presenter Name Not to scale

27 SW 4. Swell filling : Progradation Slide 25 NE 15 m 1 km Paper # Paper Title Presenter Name Not to scale

28 SW 4. Swell filling : development of rudists sandwaves Slide 26 NE 15 m 1 km Rudists sandwaves Paper # Paper Title Presenter Name Not to scale

29 SW 4. Swell filling : Retrogradation Slide 27 NE 15 m 1 km Paper # Paper Title Presenter Name Not to scale

30 SW 5. Swell filling : Progradation & emersion of the system Slide 28 NE 15 m 1 km Paper # Paper Title Presenter Name Not to scale

31 15 m Controlling factors of geometries and facies distribution Slide 29 A/S Tectonic Eustatism Paleoecology Differential aggradation Evolution of the depositional system (Shoal & swell system) Lateral variation of : Paleoecology Sedimentation rate Paper # Paper Title Presenter Name Not to scale

32 CONCLUSIONS Slide 30 Identification of new facies not yet recognized in the Al Khalij Field Depositional geometries and facies models High resolution stratigraphic architecture of Natih sequence II Controlling parameters on sedimentation processes New geological concept to constrain facies distribution in the Al Khalij field See Presentation n Outcrop analogue Al Khalij field - Caline et al. At 12h45 - Room 105 Paper n Outcrop study of the Natih Formation in Oman Robinet et al.

33 The authors would like to thank TOTAL E&P and QATAR PETROLEUM for permission to present this contribution. Slide 31

34 15 m NATIH C 60 m NATIH D NATIH C Geometries & facies distribution A B A Slide 32 C Detailed study NE SW NW B A 40 km C SE B Vertical exaggeration : x 250! 8 km A Paper # Paper Title Presenter Name

35 15 m NATIH C SW Slide 33 8 km NE Muddy deposits type 1 Bioclastic grainstone Muddy deposits type 2 Shallower Deeper Paper # Paper Title Presenter Name 2 mm

36 B 2. MEDIUM TO VERY HIGH-ANGLE DEPOSITIONAL SYSTEM Slide 34 MUD 1 Rudists MUD 2 MUD 1 Rudists MUD 2 1. SUB-HORIZONTAL DEPOSITIONAL SYSTEM MUD 1 Rudists MUD 2?

37 SEQUENCE II (60 m) STACKING PATTERNS (3 rd order) Slide 35 Top Seq. II Pure carbonate system Higher rate of accommodation Argillaceous carbonate system Low rate of accommodation Top Seq. I

38 3 m STACKING PATTERNS (High frequency) Slide 36 Shallow-up sequence Rudists Coarsening-up 10 m Burrows MUD 2 Shallowing-up Deepening-up sequence Rudists Coarsening-up x m MUD 1 Deepening-up

39 25 m 10 m B Deepening-up Vs Shallowing-up sequences A B A B Slide 37 B A C B S6 B A S6 2 km C S5 S4 S3 S2 S1 10 km

40 Paleogeography Slide 38 Paper # Paper Title Presenter Name

41 Implication of two types of mud-dominated deposits Slide 39 Well A Well B? MUD 1 MUD 1 Paper n Outcrop study of the Natih Formation in Oman Robinet et al.

42 Implication of two types of mud-dominated deposits Slide 40 Well A Well B MUD 1 MUD 1 Sub-horizontal sequences? «layer cake» model of correlation? Well A Well B Paper n Outcrop study of the Natih Formation in Oman Robinet et al.

43 Implication of two types of mud-dominated deposits Slide 41 Well A Well B MUD 1? Sub-horizontal sequences? «layer cake» model of correlation?? MUD 2 MUD 1 Paper n Outcrop study of the Natih Formation in Oman Robinet et al.

44 Implication of two types of mud-dominated deposits Slide 42 Well A Well B MUD 1 Filling of a swell Medium to very high-angle depositional profiles High lateral facies variations MUD 2 MUD 1 Well A Well B MUD 1 MUD 2 MUD 1 Paper n Outcrop study of the Natih Formation in Oman Robinet et al.

45 Implication of two types of mud-dominated deposits Slide 43 Well A Well B MUD 1 Filling of a swell Medium to very high-angle depositional profiles High lateral facies variations MUD 2 MUD 1 Well A Well B MUD 1 MUD 2 MUD 1 Paper n Outcrop study of the Natih Formation in Oman Robinet et al.

46 Deepening-up Vs Shallowing-up sequences Slide 44 Landward Landward Paper n Outcrop study of the Natih Formation in Oman Robinet et al.

47 Slide 45 Al-Husseini 2010 Paper n Outcrop study of the Natih Formation in Oman Robinet et al.