Chris Einchcomb is a Geophysical Advisor at STRYDE, with over 40 years of experience helping companies explore for oil and gas and has had first-hand experience of what it takes to design and deliver a land seismic survey that is safe, efficient, and effective.
In this blog, Chris discusses the common challenges associated with achieving survey design excellence and offers insights and advice for designing an efficient and effective seismic survey.
“It is standard practice to have the seismic acquisition contractors design the survey acquisition plan during the bidding process and in my experience, there are a few common challenges that operators face in the lead up to this which can impact the ability to set the seismic survey design process up for success. These typically include:
For smaller, independent operators, or operators who have experienced budget cuts due to fluctuating oil prices, the ability to allocate sufficient budget and resources to develop the detailed technical specifications needed for the seismic contractors to design an accurate survey acquisition plan during the bid process can be compromised. When there aren’t enough technical details available to develop an optimised acquisition plan, the logistical and operational risks post-contract award are heightened, which in turn will increase the exposure to commercial risk for the operator mandating the survey.
All too often have operators had to compromise on data quality to preserve budgets and access contractors with sufficient resources and capability. High-density image uplift is proven to help operators make informed decisions that will impact the exploration project’s success. High-density seismic can be expensive, especially in locations or for companies where cable-based systems are the preferred method for subsurface image acquisition. These preferences or ways of working will influence the specifications for the survey design, the ability to obtain high-trace density seismic, and ultimately the bottom line.
In certain regions and environment types, such as urban areas, environmentally protected rainforests, etc, operators are required to ensure their seismic operations comply with environmental regulations, therefore the type of technology that is used during acquisition, such as the receiver and source technology can be restricted, which will impact the survey costs, risk, and operational efficiencies, as well as the risk of non-compliance with environmental regulations.
The increasing cost of land and crop compensation and permitting for deforestation and restoration often leads to restricted access and / or reduction in surface equipment ultimately leading to a reduction in subsurface imaging.
Geographical restrictions ranging from the accessibility and complexity of the terrain within the planned survey parameters to the level of exclusion zones that require special permissions to conduct seismic operations. These challenges, from a geographical perspective, can cause delays in projects, additional costs, and increased HSE risks if they are not accounted for in the survey design.”
“Throughout my career, I have witnessed a number of situations where contractors have under-estimated terrain (mountains, steep cliffs, swamps, etc. haven’t been accounted for) which has resulted in the underestimation of efficiency, resources, and risk mitigation tactics - incurring lost time, delays in projects, image uplift being compromised and additional cost to both the contractor and the operator.
One real-life example of this that I can share comes from a 2D seismic survey that was conducted in the Amazon rainforest in Brazil where substantial restrictions on line-cutting exist, which caused significant challenges when laying cables out and drilling shot holes in line with the survey design. This caused the project to require more people, more equipment, and more time to assure the deliverables were met and resulted in a significant increase in the contractor’s
"This example further illustrates the importance of a fully optimised survey design and plan, and how reliant it is on obtaining accurate information, experience, and understanding of the environment."
Upon further analysis of the reasons why the survey had gone so over budget, exceeded the planned duration, and didn’t deliver the desired results, it was identified that the acquisition contractor had significantly underestimated the complexity of the terrain in the rainforest and the resources required as well as the complex logistical issues associated with getting equipment into the area.
The result? The acquisition contractor went bankrupt, and the operator didn’t get the data they needed to make critical drilling decisions and incurred substantial costs and reputational damage in an environmentally sensitive area."
“In my 40 years of helping companies explore for oil and gas in different regions of the world, working across a magnitude of terrains, I have seen my fair share of successful, adequate, and unsuccessful seismic surveys.
As I stated, survey design has a significant impact on the success, risk, and costs associated with land seismic acquisition, here are some of the key factors that I would recommend considering to help set your next seismic survey up for success:
This will pay dividends when it comes to the acquisition contractors designing an accurate survey acquisition plan and commercial model that will minimise project and commercial risks. As a minimum, the following information should be available to the contractor within this document:
A good contractor should conduct Scouting of the environment and topography they are bidding and designing a survey acquisition plan for to fully understand and account for the landscape, logistical considerations, operational efficiencies, commercial contingencies, the number of people required, equipment needed, etc in their bid.
“GIS Modelling” is a critical success factor to this process and should always be used as a technique to accurately convert the real world to the digitally and logically represented spatial objects, consisting of the attributes and geometry.
It is good practice to request the contractor to show evidence of their “Scouting Report” with the GIS Modelling results included to demonstrate they are familiar with the survey area and have a strategy in place to minimise all potential challenges that could occur during the acquisition. This should be inclusive of, but not limited to:
I have often seen further efficiencies being unlocked post-contract award, where a second on site Scouting exercise or deep dive has been conducted to fully investigate landowner requirements and additional restrictions to determine further opportunities to improve operational efficiency. I would recommend this exercise is considered for surveys that are located on complex terrains, where there are likely to be more challenges during acquisition.
Although nodal seismic receiver technology is beginning to penetrate the marketplace due to advances in technology and the industry’s need for lower cost, and more environmentally friendly seismic solutions, cabled-based receiver equipment is still a solution of choice for some countries and companies.
I have witnessed a reluctance to adopt Nodal technology due to a few reasons:
With operators increasingly requiring denser surveys at a lower price point, with reduced environmental footprint and less HSE risk, my advice here would be to remove specifications related to the seismic equipment in the tender documentation that specifies what type of receiver equipment should be used to deliver the survey. Leverage the experience of the seismic contractors and open up opportunities for them to propose alternative solutions to get a better understanding of the viable options available to acquire seismic in the most efficient and cost-effective way possible.
Small, light autonomous nodes are proven to be highly reliable seismic equipment that can be deployed with ease in all terrains, can free the survey design from spread restrictions and inefficient receiver roll limitations, allowing, in some scenarios, to achieve super dense surveys when the sources are as unconstrained, and in other scenarios, to compensate for the constraints or limitations imposed on source access and density.
Lower cost nodes are also becoming more accessible to small acquisition contractors who have greater cash flow challenges compared to multi-national companies. Managing cash flow has always been a challenge for land seismic contractors and using systems that are cheaper to lease, easier to mobilise, require less people and support infrastructure will be a big benefit to contractor’s cash flow modelling, and will ultimately offer operators a more cost-effective solution to seismic needs. This will also allow operators who mandate surveys to have a wider vendor list and support localisation initiatives where the use of local providers and labour is given a higher priority.
Don’t rule nodes out from the offset! They will reduce your exploration risks and costs and the ability to deliver higher density, better subsurface imaging.”
As the creators of the world’s smallest, lightest, and most affordable seismic nodes, we help operators in the oil and gas sector to: