Advanced Seismic Processing Methods for Imaging the Subsurface
Henning Trappe 2
Presentation Outline:
Company Profile Research Activities Introduction to CRS Processing Synthetic Acquisition Geometries & Azimuthal Processing Depth Processing: RTM against PSDM Common Diffraction Imaging CDS CRS in Nigeria Summary 3
Company Profile 4 TEEC‘s office in Hanover, Germany 5 Service Portfolio
• Seismic Processing - 2D/3D/time lapse processing - land/marine - Refraction/tomo statics - SRME/SWME demultiple - Prestack database merge
• Special Seismic Processing - CRS processing - Prestack data interpolation - Azimuth processing - High-res attributes
• Seismic Time/Depth Imaging - Velocity model building - Ray tracing - Acquisition design - Prestack depth migration - RTM
• Reservoir Characterisation - AVO processing - Acoustic/elastic seismic inversion - Coherency processing - Facies classification - Fault detection 6 TEEC’s office in Houston, Texas
TEECsolutions LLC 3100 Wilcrest Drive Suite 325 Houston, TX 7 Areas of Expertise
Headquarters Hannover/Isernhagen, Germany Branch Offices: Houston, USA Villahermosa, Mexico Buenos Aires, Argentina (Geoprocesados) Agencies: UK, China, Indonesia, Russia, Nigeria, India, Egypt 8 Areas of Expertise
TEEC is a technical partner of Mease Energy Nig. Ltd
Eke Azuka Stanley MD/CEO Mease Energy Nig. Ltd. 72 Egbelu RoadOff Rumudara, Port Harcourt, Rivers State, Nigeria. Headquarters Hannover/Isernhagen, Germany Branch Offices: Houston, USA Villahermosa, Mexico Buenos Aires, Argentina (Geoprocesados) Agencies: UK, China, Indonesia, Russia, Nigeria, India, Egypt 9 Client List ADDAX Petroleum (Switzerland) Hansa Hydrocarbons (UK) Petrotrin (Trinidad) AERA Energy (USA) Heritage Oil Ltd. (UK) Pioneer Natural Resources (USA) Anadarko (United Kingdom) Hess Corp. (USA) Pozagas (Slovakia) BEB Erdgas und Erdöl GmbH (Germany) Hess Ltd. (UK) Premier Oil (UK) BGP (China) Horizon Resources (USA) Premier Kufpec Pakistan B.V. (Pakistan) BGR Federal Institute for Geosciences and JAPEX (Japan) Qatar Petroleum Natural Resources (Germany) KBB GmbH (Germany) RAG Rohöl-Aufsuchungs AG (Austria) BG Group (UK) Layline Petroleum (USA) Ramboll (Denmark) BHP Billiton (USA) Linde Gas (Germany) Reeder Energy (USA) BP (UK) Maersk Olie og Gas (Denmark) Repsol (Spain) BP North American Gas (USA) Max Petroleum (Kazakhstan) Repsol YPF(Argentina) Cabot Oil & Gas (USA) Medusa Oil & Gas SP. z o.o (Poland) RWE Dea AG (Germany) Cabre Maroc (United Kingdom) Medco Energi (USA) RWE Dea Polska SP. z o.o (Poland) Cairn Energy PLC (UK) MND (Czech Republic) Samek International (Kazakhstan) Comstock Resources (USA) Mobil Erdgas-Erdöl GmbH (Germany) Sasol (South Africa) CGGVeritas Nadel & Gussman Rockies (USA) Shell (UK) Centrica Energy (UK) Nafta a.s. (Slovakia) Sipetrol (UK) Chevron North American Upstream (USA) NAM B.V. (The Netherlands) Sinopec Shengli (China) Chevron (UK) Network E&P Nigeria (Nigeria) Southwestern Energy (USA) COWI A/S (Denmark) NewAge Petroleum (UK) SPP a.s. Bratislava (Slovakia) Dansk Naturgas A/S (Denmark) NIS Naftagas (Serbia) Statoil (Norway) DBX Geophysical (USA) Noble Energy (USA) Sterling (UK) DMT (Germany) Oando Qua Ibo Limited (Nigeria) Sydkraft AB (Sweden) DONG A/S (Denmark) Occidental Oil and Gas Corp. (USA) TEIKOKU (Japan) EEG GmbH (Germany) OIL India Ltd. Trinity (Trinidad) El Paso (USA) OMV AG (Austria) Tullow Oil (Ireland) EnCana (Canada) PDO (Petroleum Development Oman) VITO, Flemish institute for technological E.ON Ruhrgas AG (Germany) PDOC Petrodar Operating Co. (Sudan) research (Belgium) ExxonMobil (USA) PEMEX (Mexico) VNG Verbundnetz Gas AG (Germany) Faroe Petroleum (UK) Perenco (UK) WesternGeco GdF Suez E&P Nederland (The Netherlands) PetroCanada (UK) Wintershall (Germany, The Netherlands, Libya, Gedco (Canada) Petroceltic (Ireland) Norway) Geoenergie Bayern GmbH (Germany) Petrochina Xinjiang (China) Woodside Petroleum Ltd. (Australia) Geoenpro Oil Ltd. (India) Petrochina Sichuan (China) WPX Energy (USA) Geonafta (Lithuania) Petrofac (UK) Zhibek Resources PLC (Kyrgyzstan) Petronas ( Malaysia ) 10 Research Projects
• Member of the WIT consortium (developers of CRS)
• Member of the DELPHI consortium (SRME, FWM)
• Research project PROTECT for fault detection for CO2 storage
• Research project SUGAR3: p-cable streamer, high res seismics
• SUGAR3: Advanced CRS techniques & use of multiples for imaging
• WAVE: HPC High Performance Computing
• DIFFTOMO: Benefit of Diffractions for seismic imaging 11 Fault Imaging: Standard Coherency 12 TEEC Operator (cohTEEC) 13 Advanced Software from TEECware Formats: Marine pre- processed Data Land pre- processed Data openCPS, PROMAX, Epos, su, SEGY
SRME Demultiple CRS utilities CRS basic processing - Velocity Update - Structual CRS - Gap Filling Regularised CRS gather / Geometry optimization CRS Shotgather
CRS Tomography
PrestackTime Mig. (PSTM) Prestack Depth Mig. (PSDM) Reservoir Utilities - Straight ray -Kirchhoff - cohTEEC - curved ray -RTM - neuroTEEC - anisotrophic -FWM - Modelling 14
Introduction to CRS Processing 15 CRS Time Domain Imaging 3rd party PreSTM result
2D Kurdistan 16 CRS Time Domain Imaging TEEC CRS PreSTM result
2D Kurdistan 17 Gas Storage 3D Germany onshore Standard CMP gather Shallow gas sands 18 Gas Storage 3D Germany onshore Standard CMP gather
AVO effect •Shallow gas sands
Amplitude preservation 19 Gas Storage 3D Germany onshore conv. AVO Processing
Map View after CRS-AVO 20 CRS Theory
•CRSbasic R RNIP N
NIP R = = Normal Reflector Incidence Point segment
(Mann et al., 1999) Point source at NIP: Exploding reflector R: - Emergence angle a - Emergence angle a - Wavefront curvature R - Wavefront curvature RN NIP 2 2 2 2 2 4h 2 2sin 2t cos x h 2 2 t t x 0 t h t0 2 0 v0 v0 RN RNIP vNMO 21 NMO Stack 22 CRS Stack 23 3D Northern Calcareous Alps
Austria
Munich Molasse Linz Foreland Basin Flysch Imbricated Molasse Northern Calcareous Alps 24 3D Northern Calcareous Alps CDP Gather 25 3D Northern Calcareous Alps CRS Gather, offset regularised 26 3D Northern Calcareous Alps Client PreSTM with conventional processing 27 3D Northern Calcareous Alps TEEC PreSTM with CRS processing Offshore Example: CMP Processing Offshore Example: CRS Processing 30 Norway 3D offshore Prestack data merge using CRS gathers Common processing grid 12.5 x 25.0 m bin size Acquisition E-W, 2 streamer 37.5 x 6.25 m bin size
Acquisition N-S, 8 streamer 6.25 x 25.0 m bin size 31 Norway 3D offshore CDP gathers (overlap area)
CDP gathers (overlap area) 32 Norway 3D offshore CRS gathers (overlap area) •
Xlines 950-1350: CRS gathers (overlap area) 33
Synthetic Acquisition Geometries & Azimuthal Processing 34 Irregularities in seismic acquisition 35 Data filled in by CRS gather calculation 36 Regularization onto a common grid 37 Low fold 3D dataset, onshore Germany
Original acquisition geometry 25 m bin grid
Receivers: Red Shots: Blue 38 Low fold 3D dataset, onshore Germany
CRS shot/receiver regularisation and extrapolation to 25 m bin grid
Receivers: Red Shots: Blue 39 Low fold 3D dataset, onshore Germany
CRS shot/receiver regularisation and extrapolation to 12.5 m bin grid
Receivers: Red Shots: Blue 40 Low fold 3D dataset, onshore Germany Migration without CRS, bin size 25 m x 25 m 41 Low fold 3D dataset, onshore Germany Migration of CRS gather, bin size 25 m x 25 m 42 Low fold 3D dataset, onshore Germany Migration of CRS gather, bin size 12.5 m x 12.5 m 43 Azimuthal Processing Theory
Traces of irregular CMP gather
Offset azimuth sectors : - direct azimuth decomposition - not adapted to irregular gathers 44 Azimuthal Processing Theory
Traces of regularized CRS gather
CRS offset-azimuth regularisation - using shot-receiver reciprocity 45
Data example: Raw input fold
CMP location 46
Data example: Azimuthal CRS processed data fold
CMP location 47 Pennsylvania 3D PSTM all azimuths
AGC 150 ms for display 48 Pennsyvania 3D PSTM – Azimuth changing (animation)
AGC 150 ms for display 49 A
Azimuth ALL 0-30 30-60 60-90 90-120 120-150 150-180
PreSTM cigs showing HTI anisotropy effect 50 A
Azimuth ALL 0-30 30-60 60-90 90-120 120-150 150-180 PreSTM cigs with HTI anisotropy correction Anisotropy as indication of stress and fractures
Anisotropy: indication of stress and fracture density
Direction of v_fast: indication of stress and fracture orientation Anisotropy indication of stress and fracture density v_fast – v_slow is given as percentage of the isotropic velocity
0 %: no anisotropy 1 %: “strong” anisotropy
v_fast
v_slow Direction of v_fast indication of stress and fracture orientation
In the ideal case: v_fast is directed along fractures v_slow is directed perpendicular to fractures
0 deg: north – south oriented fractures 90 deg: east – west oriented fractures N phi
v_fast
W E
v_slow
S 54
Depth Processing: RTM against PSDM Reverse Time Migration - RTM
EAGE education tour 56 North Germany 3D onshore Shot sorted input data 57 North Germany 3D onshore Acquisition geometry reconstructed CRS data 58 Depth Imaging and RTM 3D dataset, onshore India
Kirchhoff PreSDM using CRS gathers 59 Depth Imaging and RTM 3D dataset, onshore India
RTM using CRS gathers 60 Kirchhoff PreSDM with CRS gather 61 RTM with CRS gather 62 Gulf of Mexico: TEEC-RTM on CMP gather
RTM CMP 63 Gulf of Mexico: TEEC-RTM on CRS gather
RTM CRS 64
Common Diffraction Imaging CDS 65 Concept of CRS Tomography Subsurface Models (2D case) NMO Model CRS Model location location, dip, curvature
1 Parameter : 3 Parameters: , R , R vNMO NIP N 2 4h 2 2sin 2t cos2 x 2 h2 t 2 h t 2 t 2 t x 0 0 2 0 vNMO v0 v0 RN RNIP
with: Δx = midpoint distance ; h = half offset
Concept of model-independent imaging / Gelchinski (1988), Hubral (1999) 66 CDS Common Diffraction Surface
Diffractions might be useful to identify subtle
features below seismic resolution
Diffractions are characterised in CRS theory
Rn == Rnip => Rcds
TEEC established a unique approach:
Highlighting Diffractions in the seismic volume Collapse improved Diffraction through migration 67 CMP Stack 68 CDS Stack 69 CMP PSTM 70 CDS Migration 71
CRS in Nigeria 72 Location of Qua Ibo 3D
Map of Survey Area in blue rectangle Red lines show 2D seismic surveys
Source: Google Maps 73 Source and receiver map Sources: Explosives in black Airguns in red
Receiver: Receiver in brown CMP Gather 74 CRS Gather 75 Standard PreSTM IL 1100 (without CRS) 76 CRS PreSTM IL 1100 77 Standard PreSTM IL 1229 (without CRS) 78 CRS PreSTM IL 1229 79 CMP stack Timeslice 1032ms 80 CRS stack Timeslice 1032ms 81 CMP stack Timeslice 1152ms 82 CRS stack Timeslice 1152ms 83 84
Summary:
Company Profile Research Activities Introduction to CRS Processing Synthetic Acquisition Geometries & Azimuthal Processing Depth Processing: RTM against PSDM Common Diffraction Imaging CDS CRS in Nigeria 85
The End… Thank you for your attention ! 86 Concept of CRS Tomography Subsurface Models (2D case) NMO Model CRS Model location location, dip, curvature
1 Parameter : 3 Parameters: , R , R vNMO NIP N 2 4h 2 2sin 2t cos2 x 2 h2 t 2 h t 2 t 2 t x 0 0 2 0 vNMO v0 v0 RN RNIP
with: Δx = midpoint distance ; h = half offset
Concept of model-independent imaging / Gelchinski (1988), Hubral (1999) 87 Concept of CRS Tomography
RN Measurement Surface
α “relates” to reflector’s dip α RNIP “relates” to reflector’s depth
RN RN “relates” to reflector’s shape (radius of curvature) α NIP 88 Concept of CRS Tomography
Original velocity model used for calculation of synthetics
Reconstructed velocity model after CRS processing on synthetics and CRS tomography
Reconstructed velocity model with ray tracing overlay 89 Concept of CRS Tomography
Reconstructed velocity model with overlay of horizon migrated reflector elements (top). Original velocity model with overlay of same migrated reflector elements (bottom). 90
CRS versus 5D 91 Why should I use CRS processing?
I have …
… low fold data, … a low signal-to-noise ratio, … data gaps.
I need …
… a smart reconstruction of the subsurface from little data. Inline CMP stack 92 Why should I use CRS processing?
Inline CMP stack Inline 5-D stack 93 Why should I use CRS processing?
Inline CMP stack Inline 5-D stack Inline CRS stack 94 Why should I use CRS processing?
Time slice CMP stack Time slice 5-D stack Time slice CRS stack 95 Velocity model building / depth migration workflow
Time processing CRS processing Boost of signal/noise ratio Refraction Tomography CRS Nip Tomography Data driven model building (OpenCPS) (proprietary software)
shallow deep model model
FWI Start model
Multistage acoustic FWI processing QC: RTM offset gathers + depth sections (proprietary software)
Final model
Final RTM (proprietary software) 96 Acoustic FWI result
•BP 2004 model
True model
Start model
FWI model 97 Mirror migration Sea surface 98 Mirror migration Sea surface
Mirror Migration 99 Mirror migration
Mirror RTM Mirror RTM Mirror RTM Single OBS Single OBS Five OBS primary ghost ghost wavefield wavefield wavefield