Membership for subsurface professionals

Free: The Brew daily headlines, public articles and webinar recordings, all Basic Excel tools (unlicensed and free to keep), and free apps and experiments in the AI Lab.

Premium ($30/month): Everything in Free, plus the full Excel tool library (Foundation and Premium tools, all current and future, licensed for personal use), member-only access to a selected suite of interactive apps and workflows, first access to new tools and AI Lab apps as they are released to members, and 30% off Master Classes and Courses.

Lifetime ($990 one-time): Everything in Premium, kept for good, plus all AI Lab apps, Master Classes, and Courses included. Includes full source code access to all Excel/VBA, Python, and web app tools, with the right to modify and extend the code, use it in your consulting work, and deploy it internally at your company. Limited to 25 founding seats.

No. Lifetime includes all current and future tools built by Alan, the CrowdField core library.

CrowdField may also host products made by other people. Those are separate and are not included in the Lifetime plan unless explicitly stated.

• Basic tools (Free): Lightweight Excel templates and utilities. Unlicensed, free to download and keep forever.
• Foundation tools (Premium and Lifetime): The starter licensed toolkit, including IARF Pressure Profile, Gas Darcy Inflow, Gravity to DeltaP, Log-Log Drawdown, WPIMult to Skin, and others.
• Premium tools (Premium and Lifetime): The full library, including the DCA Tool, RFT Tool, PZ Mat Bal, Rel Perms, Montecarlo Volumetrics, Critical Lift Rates, Well Valuation, Economic Modelling, and every future tool added to the library.

Premium and Lifetime members get the complete library (Foundation plus Premium). Lifetime members additionally get the full source code.

Yes. Lifetime is limited to 25 founding seats. When they are gone, Lifetime closes and comes off the page.

Only these 25 founding seats carry everything with no end date, including every tool, app, course, and workflow released in the future. If a lifetime option returns later, it will be a narrower offer: the current library plus a set period of future releases, not an open-ended grant. The founding seats are the only ones that never expire and never stop adding new tools.

Yes, while founding seats remain. Lifetime is limited to 25 founding seats, and each upgrade takes one of them. If you upgrade within the first 12 months of a Premium subscription, we credit what you have already paid in Premium fees against the $990 Lifetime price. After 12 months, the Lifetime price applies in full. Once the 25 seats are gone, Lifetime closes and the upgrade path closes with it, so if Lifetime is where you want to land, it is safer not to wait. Reach out and we will handle the upgrade and credit manually.

Master Classes and Courses cover practical workflows in Excel/VBA, Power Query, no-code tools, Python, and AI for subsurface professionals.

• Free: Pay full price per cohort.
• Premium: 30% discount on every cohort.
• Lifetime: All Master Classes and Courses included, current and future.

All Premium-licensed tools run through a simple licensing system to keep things fair:

1. Download the License Request Form from your welcome email and run it to generate your machine ID.
2. We send you a custom license file and a link to your tool repository.
3. Open an Excel tool and browse to your license file when prompted.

The license is cached, so you will not be asked again unless your system changes. An internet connection is required when opening files so the system can validate your active subscription.

Premium members: Tools are locked and run via the licensing system. The VBA code is not accessible. This keeps the licensing system intact and the subscription price affordable.

Lifetime members: Tools are delivered with full source code access. You can view, modify, and extend all VBA, Python, and web app code. The Lifetime license also grants commercial use rights, so you can use the tools in your own consulting work or deploy them internally at your company.

Individual purchases: If you buy a specific tool at full price outside of a membership, it may be delivered unlocked with full VBA access. This is the only other path to source code outside of Lifetime.

Premium licenses are bound to a single PC (Machine ID). If you use a work laptop and a home desktop, get in touch and we will arrange a second activation. For team or company-wide use, Lifetime is the appropriate path: the commercial license covers internal deployment across your team.

Yes, on a best-endeavours basis. User feedback is actively built into the tool roadmap. Minor improvements are often added quickly. Larger feature requests may be scheduled for a future release.

Yes. Premium is month-to-month. You can cancel directly through your Stripe billing portal. Your access remains active until the end of your current billing cycle.

Licensed Excel tools stop working when your Premium subscription expires. The Basic Excel tools you downloaded as a Free user remain yours forever and continue to work. Lifetime is unaffected by cancellation: once you have purchased Lifetime, your access and source code rights are permanent.

Yes. $990 once. No recurring charges, no expiry, no renewal. As one of the 25 founding seats, you keep access to every current tool, app, course, and workflow, plus everything released from here on, with no end date. Source code and commercial rights are permanent.

For Premium, you can cancel at any time and your subscription will not renew. We do not typically refund partial months once charged. For Lifetime, given the scope of what is included and the source code access granted on day one, all sales are final. If you are unsure whether Lifetime is right for you, start with Premium and upgrade while founding seats remain (the credit applies for the first 12 months).