Bohai Bay

Asset overview - Bohai Bay


Bohai Bay, offshore China
27.7km2 production license: Zhao Dong Block
16km2 exploration/appraisal block: Zhanghai
26km2 exploration/appraisal block: Chenghai

Operator Dagang Zhaodong Oil Company (PetroChina Company Limited)
JV partners and interests
Zhao Dong Block Zhanghai & Chenghai Blocks
Development Interest (including C&D fields) Development & Production
Exploration & Appraisal
Roc Oil (Bohai) Company 24.5% 39.2% 80%
Dagang Zhaodong Oil Company (PetroChina Company Limited) (Operator)
75.5% 60.8% 20%

Producing oil from Zhao Dong Block fields: C&D. Activity is focussed on production optimisation

The Zhao Dong offshore facilities comprise four bridge-linked platforms; two for drilling and accommodation and two for production and processing.

Oil and gas production is delivered to onshore refinery and gas sales by pipelines.

First production Commenced in 2003 from the C&D Fields.

The Bohai Bay is a prolific oil producing province with stacked reservoirs system, ranging in age from Palaeozoic to Tertiary.  Reservoir quality is good to excellent.  The source rock is rich and generative.

The Zhao Dong Block is extremely oil prone and oil is generally found wherever a suitable trap exists.  Within the Block, 27 different stratigraphic levels are known to contain oil; 16 of these are currently productive.  Oil is waxy with a low pour point and a low acid content.


Zhao Dong Block

ROC acquired a 24.5% operated interest in the Block in mid-2006 via the acquisition of 100% of the shares in Apache China Corporation LDC.  The Block contained the C&D fields which commenced production in 2003 and part of the C4 field.  At the time ROC acquired the asset, approximately 20 MMBO had been produced from the C&D fields.

The fields produced and underwent simultaneous continuous development.  Since acquiring the asset, the ROC-led joint venture drilled over 170 development wells in the block, installed two platforms adjacent to the existing Zhao Dong platforms and installed new facilities at C4.

ROC initiated a continuous improvement process and established action teams to enhance teamwork, operating efficiency and cost effectiveness.

Operatorship was transferred from ROC to PetroChina on 5 April 2015.  ROC continues to play an active role in the ZD project and supports the new operator to ensure safety and efficient operation.

On 28 August 2018, the Zhao Dong PSC Extension Agreement was signed by ROC and PetroChina to extend the Zhao Dong fields' production period from September 2018 to April 2023.  During the extended production period, participating interests in production from future wells are PetroChina 75.5% and ROC 24.5%.

A committed program of 24 new wells to be drilled in the first two years of the extended production period was completed by year-end 2020.  ROC is only entitled to oil from any new wells drilled post 5 September 2018.  

ROC withdrew from the unitised C4 field in early 2020, effective 31 December 2019.

ROC is leveraging on the Company's Zhao Dong experience and infrastructure to support a long term growth plan in China.

Zhanghai and Chenghai Blocks

In March 2011, the existing Petroleum Contract covering the Zhao Dong Block was modified to include these adjacent blocks with the aim of commercialising previous near field discoveries in the area and encouraging further exploration activity.  Any potential commercial development in the Blocks would utilise the existing Zhao Dong facilities.