INPEX CORPORATION (INPEX) announced today that it will conduct short-term flow tests to gauge the capacity of exploratory wells it has drilled in the Oyasu region of Akita Prefecture, Japan in partnership with Idemitsu Kosan Co., Ltd. and Mitsui Oil Exploration Co., Ltd., with which it has jointly pursued commercialization studies on
geothermal power generation since 2011.
1. Details and objectives
The short-term flow tests will be conducted on two exploratory wells* drilled during the
current fiscal year. The tests will evaluate production capacity based on a constant flow over
a 1~2 week period using wells similar in size to actual production wells. Through these
experiments, the companies will verify details concerning well production capacity (volume of
steam), underground temperatures, chemical composition of geothermal fluids, water
permeability in the vicinity of the well and other matters.
* Exploratory wells are similar in size to actual production or injection wells, and are used to
conduct production and injection tests over several weeks.
2. Overview of studies to date
(1) Stage 1: Completed in FY2011
Superficial surveys (ground-level geological surveys, gravitational exploration, electromagnetic exploration, etc.)
(2) Stage 2: Completed in FY2017
(i) Drilling survey, building roads for equipment transportation, etc.
Drilling exploratory wells to study geological structures, underground temperatures and water permeability
(ii) Hot spring monitoring survey
Monitoring hot spring temperatures, yields, and chemical composition at nearby hot spring wells
3. Future schedule
INPEX and its partners will conduct the third stage of studies including (1) production and
injection experiments, (2) reservoir capacity assessments, (3) environmental impact studies,
etc. from FY2018 to FY2021.