Since 2013, INPEX has conducted information gathering and technical research to start shale oil / gas development projects in North America. For the results of 5years of research，INPEX decided to purchase Eagle Ford shale oil / gas asset from the previous operator in 2018. Also, we recognized cultural differences in shale development industry from conventional petroleum research & development industry from this research. There are some gaps between the previous operator’s standards and INPEX technical standards.

INPEX intended to follow the basic operation of the previous operator but was forced to modify some operation specification or procedure to ensure our technical standards.

In this paper, we introduce the INPEX’s first shale oil / gas field development project in North America including some discussions made to ensure the safety of this project.

The content of this presentation is as follows,

1. Background of the project

2. Project summary

3. Basic well design

4. Our drilling engineering

The resource development of marine methane hydrate deposits will require drilling of considerable numbers（tens to hundreds）of wells in relatively shallow and unconsolidated formations beneath deepwater due to limited area of drainage of each well. Safety and cost reduction of drilling operation could be a critical technical challenge of the development of the unconventional energy resource. The Japanese national gas hydrate resource program lead by MH21 research consortium performed twice gas production tests from gas hydrate deposits in the eastern Nankai Trough in 2013 and 2017 and drilling engineers have encountered many technical challenges and solved them for the successful testing. Among them, three technical challenges; pressure corning technology that allowed the sampling of high quality gas-hydrate bearing samples, an attempt of wash over operation for the recovery of a sand control device that had been buried with produced sand in the previous year, and screw back troubles happened on drilling strings due to ocean currents and countermeasures to them are reported in this article.

Supercritical geothermal power generation is a next-generation geothermal power generation using geothermal fluid that exists in deeper formation than conventional geothermal reservoir and is in a supercritical or subcritical state in subsurface environment. The steam production capacity per production well of supercritical geothermal power generation is estimated to be several times higher than that of conventional geothermal power generation. Drilling and completion of supercritical geothermal wells under harsh conditions assuming an ultra-high temperature above 400°C and H₂S and/or HCl acidic corrosion environment with very low pH, and maintaining the well integrity for about 40 years of commercial power generation, are a challenge to overcome the extremely difficult technical issues compared to the conventional geothermal development. In this lecture paper, current status of domestic and worldwide supercritical geothermal resource development is reviewed and the technical issues in drilling and completion of supercritical geothermal wells are discussed.

The 1st large scale Carbon dioxide capture and storage（CCS）demonstration in Japan aiming for the practical application of CCS technology has been conducted by Japan CCS Co., Ltd.（JCCS）, commissioned by Ministry of Economy, Trade and Industry（METI）, New Energy and Industrial Technology Development Organization（NEDO）.

The demonstration facilities including two directional injection wells to offshore reservoirs were constructed in the port area of Tomakomai City, Hokkaido from FY2012 to 2015.

The CO₂ injection at scale of 100 thousand tonnes per annum was started from April 2016 and achieved initial target of 300 thousand tonnes cumulative injection on November 22, 2019.

This paper introduces the outline of CO₂ injection wells focusing on well completion.

Japan Agency for Marine-Earth Science and Technology（JAMSTEC）owns drilling vessel "Chikyu" and conducted the drilling operation at Nankai Trough Area as one of scientific drilling projects. We have drilled total over 70 holes（Riser/Riserless holes and monitoring wells）at this area until 2019. Riser hole at C0002 site was the one of the main well for the earthquake research field and drilled step by step in 2010, 2012 and 2013. To reach the plate boundary fault, the drilling program of deepening C0002 riser hole during International Ocean Discovery Program（IODP） Expedition 358 in 2018 was planned. For succeeding the drilling operation at C0002 riser hole, geomechanics, expandable casing, continuous circulation system and mud rheology including sealant were discussed and prepared.

This paper introduces the operation results and preparations of IODP Expedition 358.

Japan Drilling Co., Ltd.（JDC）has been drilling in various waters around the world as an offshore drilling contractor. In recent years, the momentum for introducing renewable energy has been increasing toward the realization of a carbon-free society worldwide. Regarding the offshore wind power business, which is being introduced mainly in Europe, the development of legal systems and the construction of special vessels for installation work is progressing in Japan as well in order to expand the introduction. However, there are many issues in introducing offshore wind power, and among them, there are few companies in Japan that have knowledge about offshore operations. Therefore, JDC also wants to establish a system to provide a wide range of services in order to make offshore wind power one of its businesses.

In this lecture, we will introduce the technical services that JDC will develop in the offshore wind power business by utilizing the experience and knowledge that JDC has cultivated in offshore drilling.

Drilling industry faces multitude of challenges ranging from resources constraint driven by activity volatility, increasing demand for cost efficiency and its expansion into non-conventional oil and gas drilling such as unconventional resource, carbon capture and storage（CCS）, geothermal etc. The geothermal industry in Japan encounters those challenges in addition to higher requirements for drilling efficiency improvement and health, safety and environment（HSE）accountability. These challenges call for a more accurate and extensive well construction planning solution, where operator can mitigate drilling risk and improve the drilling efficiency from the planning phase. The solution shall inherently drive efficiency well planning process where less resources would be required. An innovative well construction planning solution on cloud has been developed to cover all different aspects of the well planning and engineering workflows, delivering a step change in terms of capabilities and efficiency. The capabilities and efficiency are achieved through digital technology combining automatic engineering and validation, big data analytics, concurrent engineering, and project orchestration. Recently the trend of utilizing cloud based digital technology is increasing in the international drilling industry, and one trial project was conducted for a domestic geothermal well construction planning. The efficiency gain and quality improvement of well planning were evidently demonstrated in the trial project with the various positive feedback from the user. The trend of cloud utilization is expected to continue increasing.

Fine-grained clastic rocks of the Miocene Nanatani Stage（17.0-12.3Ma）in the northern Niigata and central Yamagata areas, northern Japan, record the transitional phase from the syn-rift to post-rift regimes related to backarc spreading in the Sea of Japan. They are characterized in places by biosiliceous lithology, often with a relatively high content of sedimentary organic matter. Observations of rock facies along with the results of the total organic carbon, RockEval, and X-ray fluorescence analyses of outcrop sections revealed that the organic matter content was primarily controlled by the enhanced primary production of photosynthetic algae in the northwestern Pacific since the Middle Miocene. This global-scale process was modified locally by regional tectonics in terms of the rate of clastic input and subsea topographic relief, which possibly served as a barrier to ocean circulation. This explains the tens of kilometerscale lateral variations in the source rock potential, as well as the time lags of the organic matter accumulation between the basins within the coastal region of the Sea of Japan.

We re-discovered tight/shale oil accumulations through a successful acid treatment in the Onnagawa Formation, the main petroleum source rock in Japan, which is Monterey-like biosiliceous shale of the Middle Miocene age. Its productivity is fairly high, comparable with that of the Bakken shale, and is supported by matrix pores of quartz-porcelanite and carbonate-cemented natural fractures which is stimulated effectively through acidizing. The tight oil horizon corresponds to the best source and the best reservoir rocks. It is the most siliceous part of the formation, which is reasonably understood as a result of an increase in primary productivity with diatom blooms in the Miocene age. We think the tight oil is generated in situ and a part of continuous accumulation, while it is in a structural trap so far. The above exploration concept will be applicable to the Monterey Formation of California and the Dae-Khurie Formation of Sakhalin, which are siliceous rocks of same type, and re-evaluation of non-commercial hydrocarbon flows or shows in exploratory wells is recommended.