Geophysical Acquisition Specialists Promoting the Highest Standards - PowerPoint PPT Presentation

Geophysical Acquisition Specialists Promoting the Highest Standards

SEISMIC OVERVIEW What is a seismic survey? Operations - The stages of a seismic job Government Approvals Land permitting Line construction Line survey Data acquisition Clean up and reclamation SUCCESS IS NO ACCIDENT

What is a Seismic Survey Seismic testing has revolutionized the oil and gas industry. Seismic surveys have • become the primary tool of exploration companies in North America. Seismic surveys have lowered finding costs and allowed exploration of reserves not found by previous means. The industry has also embraced seismic in an effort to reduce environmental risk. Seismic surveys can be conducted in almost any environment-in the ocean, in swamps • and in urban areas. There are three phases to seismic surveys: data acquisition, processing and interpretation. Data Acquisition: • A seismic survey is conducted by creating a seismic wave on the ground along a predetermined line, using either small explosive charges set off in shot holes or by a vehicle (Vibroseis truck) with plates that vibrate on the ground.

What is a Seismic Survey Each energy source will send a seismic wave into the earth and when reflected by • subsurface formations, the sound will return to the surface and be recorded by receivers called geophones. By analyzing the time it takes for the seismic waves to reflect off subsurface formations and return to the surface, a geophysicist can map subsurface formations and anomalies and predict where oil or gas may be trapped in sufficient quantities for future exploration activities.

What is a Seismic Survey Data Processing: • The data recorded from a seismic survey is originally in its unprocessed or raw form. In order for it to be interpreted, it must go through a series of computerized tests. These processes include filtering, stacking, migrating and other computer analysis which make the data usable during the interpretation process. Data Interpretation: • Finally, the resulting processed data must be interpreted by the geophysicist or geologist. All seismic data is subject to interpretation and no expert will interpret data identically. The proper interpretation of seismic data is a critical and important step in oil and gas discovery.

What is a Seismic Survey Put Simply: A seismic survey is the mapping of the earth’s sub -surface. It is like an ultrasound on the earth. By inducing source energy into the earth’s subsurface , geophysicists & geologists are able to create an image of the various layers and formations that comprise the sub-surface. The objective is to identify pockets of gas, oil, or other usable deposits. Once a specific location is identified, leases are constructed and drilling commences.

Operations – The Stages of a Seismic Job Government Approvals • Land permitting • Line construction • Line survey • Data acquisition • Clean up and reclamation • These phases usually occur in a sequential order, • overlap does occur.

Operations – Land Permitting Negotiation between the energy company (client) or its agent, • and land owners. Negotiate for permission to perform work on an owner’s land. • Land owner’s are compensated and can set rules or • stipulations.

Operations – Line Construction Mulchers, small Cats, Tractor and Chainsaw operators • Cats and Tractors can be used clear roads and existing access of • obstructions or snow Mulchers are used cut and mulch trees/vegetation to open up source • and receiver lines while minimizing the affects on the ground Chainsaw operators clean the lines the mulchers create (make the line • safe) as well as hand cuts lines in areas where mulchers and other equipment are not allowed Larger mulchers cut “Source” lines 2.5m and wider • Small mulchers cut “Receiver” lines as small as 1.75m wide • Source lines will be travelled by the Vibes, therefore they need to be • wider Receiver lines are typically walked and travelled by ATVs and or • snowmobiles

Operations – Line Construction Larger Size Mulcher

Operations – Line Surveying Identifying and marking source and receiver points on the lines the mulchers • have cut. Surveyors use sophisticated GPS to locate and mark points. • They usually use ATVs to travel the lines. • Each point on a source line is the location where the source energy will be • either vibrated or detonated on The points located on receiver lines are the locations for planting the • geophones

Operations – Line Surveying Each point on a receiver line is a location where instruments • will be placed to record the shock wave created by the vibration on the source lines. Surveyor Quad Mounted Survey Unit

Operations – Safety On site Medics and emergency transport vehicles • are used for remote locations

Operations – Safety Daily safety and operations meetings are conducted with the crews

Operations – Data Acquisition Commonly referred to as the recording phase. • Usually the biggest crew of the process, upwards of 60 people. • Objective is to plant instruments on receivers lines and vibrate • on source lines and record the reflected energy wave as it reflects off of sub-surface structures. Party Manager • Observer(s) • Safety Advisor • Coordinator • Vibe operator • Trouble shooters • Line crew •

Operations – Data Acquisition Process: • Party Manager manages the crew • Coordinator directs the line crew • Line crew lays out cable • Trouble shooters fix problems • Vibe operator operate the vibes and vibrate on the source points • Observer directs trouble shooters and vibe operators, and also • manages and compiles the data as it is acquired Line crew picks up all the cable and instruments (geophones) • after recording is complete Equipment used • Pick up trucks, ATVs, snowmobiles, trailers & helicopters •

Operations – Data Acquisition Staging area with recording equipment on the ground.

Operations – Data Acquisition On larger projects helicopters are used to deploy & recover recording equipment

Operations – Data Acquisition Larger Vibe

Operations – Data Acquisition Wireless recording system placed on each station.

Operations – Data Acquisition Deployed 3C geophone using a wireless system

Operations – Data Acquisition Final Product

Operations – Clean Up & Reclamation • Cleaning all waste left behind by operations • Removing bridges and corduroy • Inspecting all lines and access, addressing issues found • Any task requested by land owners and/or Forestry Officials