Where do we Start
It is essential to start with the accurate location of the wells. If the solution methods are based on reactive measures, the problem never goes away. Waiting for wells to lose integrity and fail resulting in surface evidence is not the answer.
Determining location first, minimizes risk and has increased benefit to multiple parties. Every time a well is drilled, there is enough doubt as to P&A wells previously drilled nearby, that tools are equipped with sensors to perform collision avoidance. If the location of those wells were known in advance the risks could be assessed more accurately in advance.
Reservoir analytics are based on knowledge of the well data being used. Uncertainty in well locations creates bias in those analytics and as such the criteria of use must be adjusted to compensate for uncertainty.
As we gradually move towards renewables and attempt to counter environmental aspects such as carbon capture, and in-ground methane storage there are unknown risks due to P&A well integrity concerns and
absolute location certainty. External leakage and possible blowouts are possible as has been evidenced with enhanced oil recovery methods. Not knowing the location of wells precisely limits their use and increases risk and cost of all aspects of well operations. These issues; while being minimized through best practice, internal operator well evaluation and due diligence prior to drilling or use are still reactionary and not a solution.
There is a great need to involve the operators and get them to realize that access to well data is beneficial to themselves and in resolving the issues of uncertain location. Previously held beliefs that well locations were proprietary are no longer valid in the age of highly accurate satellite and aerial imagery. Given the drive to regulate responsibility for all wells located within an operator’s lease, the idea of willful ignorance of Orphan and older P&A well failures are also outdated.
The same is true for commercial and public data vendors. While years of effort and cost have gone into collecting, correcting, and supplying clients comprehensive well data, the locations contained within their own data bases are subject to uncertainty and often conflict with other sources of the same information. Public sources such as the TRRC data are especially suspect and generally trail both the private and proprietary sectors in location accuracy.
Getting parties to agree to participate and exchange information is where we must start. Unless all parties agree to exchange location information any effort not involving both industry, commercial and public efforts will likely fail. However, there are ways to begin the process and show benefit to all parties without upfront commitment.
What are the Steps to Ensure Success
Start with public domain data – TRRC: The TRRC is the primary source for well location data due to its primary tasks of permitting wells and protecting landowners. While the SHL locations are often suspect it is the logical starting point to correctly classify well data, identify Orphan and P&A wells, and create a well data governance system to enhance the protection of Texas landowners.
Involve domain expertise: In order to resolve well locations a proper supervisory team must be put in place to enable the task of identifying and locating Orphan and P&A wells. That team should have prior experience in the forensic sciences of identifying both visible and non-visible wells. They need the skills of surveying and all aspects of Geomatics, including remote sensing and GIS data management. They should have the added benefit of being able to train a work force to continue these tasks well into the future.
Create a data governance structure to establish integrity in final results: Any effort must at its core, create a data governance process which ensures the continued integrity of the processes and work performed, both for existing data and for future data.
Classify all wells to enable targeted effort: Because all well locations are suspect due to missing metadata or standard governance, the initial efforts should not be limited to Orphan and P&A wells, but all wells. A basic well classification system should be put in place which identifies the hierarchy of need. This may be as simple as identifying which wells are visible in imagery (both historical and current) and which are not.
Go through archives and identify missing wells: Part of the forensic efforts require digging through both digitized/scanned hard copy documents and physical documents. The TRRC has a document management system. That system needs to be refined to include additional search criteria to gather specific document types like survey plats, well headers, lease maps and oil company production maps.
We know that once a well reaches inactive status (no production for a year) the TRRC is no longer responsible for the well (in their mind) that is why there are 1.21 million wells that they are no longer monitoring. The “Orphan wells” that are described above are included in this number. However, wells like
these and the thousands of other old legacy wells that we see on the old topo maps are probably not included in this total number.
Create an API assignment for historical wells and group by risk/year: Commercial well data providers have assigned many historical wells with their API numbers. TRRC only provides the county level 3-digit API prefix, which is inadequate for deep searches. Well name(s), API number, Abstract, block and section along with other land grid designations need to be captured along with other critical metadata and added to the well data information.
Publish wells requiring field location: Following initial classification processes and data gathering, all Orphan and P&A wells without specific documented locations, should be published and targeted for field location. By gathering wells grouped by location, and date drilled/plugged/abandoned; risk can be
assigned, and efforts can be put in place; which enable necessary methods, including remote sensing, ground detection and field survey. It also provides operators with improved risk assessment and may induce efforts to review local Orphan and P&A wells within their area of operations.
Make data available to public, commercial and industry for fee or data trade: The easiest way to garner industry support is to provide value for the fees, taxes and regulations put in place. The TRRC as a protector of landowners, are also a key source for information about the oil and gas industry. All data held
by the TRRC is geospatial in nature and as such delivering information that is properly identified by location is value added. It is possible that delivering location information that has current and ongoing integrity along with the related metadata has potential to reduce cost and to increase revenues.
A second opportunity exist to combine data trade in exchange for services provided. Much of the key information is held by commercial and private entities. Engaging those entities to allow use of the position related data allows the resulting efforts at locating wells to be value-added to their commercial efforts.
Adopt IOGP P7 positional exchange format for import and export of well positioning data: Historically well positions have been provided by means of calls or surface hole location and with the advent of horizontal drilling, take points and bottom hole location. These are always provided in document form,
which creates costly effort to extract the information and place in digital form. This too has been a source of positional error. The result of positional exchange work by the International Oil and Gas Producers Association (IOGP) has yielded the IOGP P7 wellbore exchange format, a digital representation of well positioning data. This format should be required for both receipt and delivery of newly permitted and drilled well positional information.