I'm not sure. The definition of a security is pretty broad. My guess is no. Unless your arrangement is transferable without the knowledge or permission of the owner of the minirig, then yes it could be a security.
(1) The term "security" means any note, stock, treasury
stock, security future, security-based swap, bond, debenture,
evidence of indebtedness, certificate of interest or participation
in any profit-sharing agreement, collateral-trust certificate,
preorganization certificate or subscription, transferable share,
investment contract, voting-trust certificate, certificate of deposit
for a security, fractional undivided interest in oil, gas, or
other mineral rights, any put, call, straddle, option, or privilege
on any security, certificate of deposit, or group or index of securities
(including any interest therein or based on the value
thereof), or any put, call, straddle, option, or privilege entered
into on a national securities exchange relating to foreign currency,
or, in general, any interest or instrument commonly
known as a "security", or any certificate of interest or participation
in, temporary or interim certificate for, receipt for, guarantee
of, or warrant or right to subscribe to or purchase, any
of the foregoing.
This is where they grab your balls and squeeze hard. I guess the option is: now promise of profit sharing.
In the case of a straightforward equipment lease, I don't think there's profit sharing going on. You lease a piece of equipment, you get 100% of the profit from it. You use that profit to pay the lease.
Now if you pool funds to pay the lease, and split the profits, then you're definitely in securities territory.
Or if you lease fractions of a piece of equipment, then there is the potential that the lessor is in securities territory.
I don't think anyone is going to consider these lease situations a security though unless the lease contracts are transferable. (thus, resembling a "share")