CARROLL

STARK

COLUMBIANA

MAHONING

JEFFERSON

PORTAGE

TUSCARAWAS

T16NR4W

T17NR4W

T15NR4W

T14NR5W T13NR4WT15NR6W

T17NR5W

T16NR5W

T18NR5W

T17NR6W

T15NR5W

T20NR7W

T18NR6W

T16NR6W

T19NR7W

T18NR7W

T19NR6W

T16NR7W

T14NR6W T13NR5W

T16NR3W

T15NR3W

T14NR3W

T13NR3WT14NR4WT14NR4W

T11NR3W

T17NR7W

T15NR7WT12NR4WT12NR4W

T12NR3W

T12NR3W

T17NR7W

T15NR7W

T1NR8W T1NR7W T1NR6W T1NR5W T1NR4W T1NR3W

81°W

81°W41

°N

FIRESTONE 3DMULTI-CLIENT 3D SEISMIC SURVEY

0 2 4 6 81

Kilometers

N: \Pub lic\GI S\ Arc Map Do cu me nts\Onsho re \Specshee ts\Fireston e 3D spec (p ort) .mxd Octo ber 2 3, 20 13

OHIO

Serv ice Layer Credits: Sources: Esri, DeLorme, NAVTEQ, TomT om, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN,Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, and the GIS User Community

TGS Well Logs Available

Firestone 3D

FIRESTONE 3DPRE-STACK TIME MIGRATION (PSTM)

MULTI-CLIENT 3D SURVEY

ACQUISITION PARAMETERS

Acquisition Date: May 2012 – February 2013 Receiver Interval: 220 ft

Source Interval: 220 ft (245.9 ft diagonal) Receiver Line Spacing: 880 ft

Source Line Spacing: 1320 ft Geophones: 6, 10 Hz linear array

Record Length: 5000 ms Sample Interval: 2 ms

Multiplicity (Nominal): 130 Recorded Bin Size: 110 x 110 feet

Source Type: Mixed source: 3 Vibrators with 2 sweeps x 12 s, 6-120 Hz, linear sweep 2.2# dynamite at 30 ft

Maximum Offset: 19382 ft Template: 20L x 156 stations per line, roll one line

Receiver Orientation: West - East Surface Area: 409 mi² Acquired By: Tidelands Geophysical

PRE PROCESSING Processed by Arcis in Calgary – Completed August 2013

Input SEGD data Merge navigation with seismic trace headers Geometry QC, trace edits Output geometry shot ordered tapes Spherical divergence correction Noise attenuation, shot domain Surface consistent amplitude compensation Refraction statics Noise attenuation, shot domain Surface consistent deconvolution Velocity Analysis

Residual de-noise Second pass of surface consistent amplitude compensation Reflection statics Second pass velocity analysis Second pass of reflection statics Surface consistent statics and Phase Correction ETA estimation Third pass velocity analysis Output pre-processed data with refraction and

reflection statics stored in trace headers

TIME MIGRATION and POST-STACK PROCESSING

Kirchhoff pre-stack time migration velocity analysis (2 passes) Output migration velocities ( 0.25x0.25 mi) Anisotropic Kirchhoff pre-stack curved ray migration (input-output grids

110x110 ft) Output raw migrated gathers with NMO Mute and stack

Output raw migration Apply filter and scale Noise reduction and footprint attenuation Output processed migration

AVAILABLE PSTM DELIVERABLES

Raw field data / shot ordered (SEGD) Field data with geometry and XY coordinates in the trace headers/shot

ordered (2 ms unedited) Preprocessed data – with refraction and reflection statics stored in trace

headers (CDP sorted) Pre-stack time migrated CDP gathers with NMO

Raw migration Processed migration Migration velocities (ASCII, 0.25x0.25 mi) 3D migration velocity trace volume Processed land source-receiver navigation – (SPS) Data processing final report

FIRESTONE 3D PRE-STACK DEPTH MIGRATION (PSDM)

MULTI-CLIENT 3D SURVEY

PROPOSED ANISOTROPIC KIRCHHOFF DEPTH MIGRATION (Optional)

Build initial vertical velocity model by calibrating PSTM velocities with check shots Remove long wavelength statics from data and move data to acquisition datum Kirchhoff depth migration Estimate anisotropic parameters delta and epsilon These parameters apply to all migrations and tomography iterations: input-output grids: 110x110ft, nominal fold 45, max depth 20000 ft, aperture 20000 ft,

tomography cells 660x660x165 ft, depth step 30 ft model building, final output depth step 20 ft Iterations I-III Anisotropic VTI Kirchhoff PSDM and tomography updates Iteration IV Anisotropic VTI Kirchhoff PSDM and tomography update (if required) Final VTI Kirchhoff PSDM Output migrated gathers without residual NMO Residual moveout Output migrated gathers with NMO Mute and stack Output raw migration Noise reduction (f-k power or fxy deconvolution) Amplitude balance and TVF Footprint removal Output processed migration

PSDM DELIVERABLES

Kirchhoff pre-stack depth migrated gathers – no residual NMO (raw) Kirchhoff pre-stack depth migrated gathers with residual NMO (processed) Kirchhoff pre-stack depth migrated stack – raw Kirchhoff pre-stack depth migrated stack - processed Final velocity volume – unsmoothed (interval velocities) Final anisotropy delta field Final anisotropy epsilon field

The processing flow and parameters published herein are the anticipated flow and parameters for the survey and TGS will use commercially reasonable efforts to follow this flow and parameterization. However, the foregoing notwithstanding, TGS reserves the right to modify the processing flow and parameters as needed to adjust for timing, testing, and new technologies.

14 July 2014