日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS02] 地球掘削科学

2019年5月27日(月) 15:30 〜 17:00 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:山田 泰広(海洋研究開発機構 海洋掘削科学研究開発センター)、針金 由美子(産業技術総合研究所)、黒柳 あずみ(東北大学学術資源研究公開センター東北大学総合学術博物館)、山口 耕生(東邦大学, NASA Astrobiology Institute.)

[MIS02-P02] In-situ rock strength calculated from drilling parameters. Comparison of results from various sites.

*Adam Wspanialy1Yasuhiro Yamada1Saneatsu Saito1KYAW MOE1 (1.Japan Agency for Marine-Earth Science and Technology)

キーワード:rock strength, drilling parameters, Specific Energy

Drilling parameters are excellent datasets to understand in-situ physical properties of the rock. Continuous core samples along with parameters such as Torque, RPM, WOB and ROP have been collected during drilling operations. The borehole data acquisition was complemented with full LWD/MWD and wireline logging. After core delivery to surface core scratch tests have been carried out to measure Unconfined Compressive Strength (UCS). Our comprehensive approach enabled us to integrate all data and conduct detailed analysis of the in-situ subsurface physical and mechanical properties of a rock cut by a drill bit.

Here we present some results from offshore and onshore drilling experiments carried out in Japan, Oman and Australia. Methods such as Specific Energy (SE) and Equivalent Strength (EST) have been used to estimate in-situ rock properties, namely UCS and analyse drilling process.

Our results demonstrate that the calculated in-situ rock strength based on SE/EST methods correlates well with sonic derived UCS and core scratch derived UCS. Utilised methods also successfully detect fractures in the formation, show developing drilling dysfunctions such as vibration, and bit balling.