A very informative paper.

http://findarticles.com/p/articles/m...

In my opinion, the recent news release regarding the unitization of the Mako field

clearly falls under the category of "pre-unitization"

Outside the United States, because unitization agreements usually involve larger prospects, bigger sums of money, and unitization at an early stage of a field's development, it is useful to think of three stages to unitization, as follows:

(i) the pre-unitization agreement (entered into at the time of discovery [or appraisal] of a common reservoir, generally before commerciality is declared);

(ii) the unitization agreement (usually coincident with an agreed development plan); and

(iii) redetermination of participation factors (as specified in the unitization agreement) as more data becomes available from field development and production.

A. Pre-Unitization Agreements

Because of the complexity of unitization and the time consumed negotiating a full unitization agreement, participants in the blocks to be unitized may enter into a pre-unitization agreement to allow preliminary work to be conducted while negotiations are proceeding. This preliminary work often consists of joint technical studies designed to help determine the extent of the field or reservoir to be unitized and the quantities of oil and gas in that field or reservoir that underlie each block (which will be used to determine relative tract interests, as described below in subpart V.D) and may include the drilling of jointly-funded wells. Pre-unitization agreements sometimes appoint an initial unit operator to conduct this work and, regardless of whether an initial unit operator is appointed, will generally authorize the party conducting the work to charge the applicable costs to all parties based on an interim allocation. The interim cost allocation will be adjusted following unitization.