China

Landmark: China’s First Subsea Completion Project with Overtrawlable Structure

Project Overview

• Contract Award: 1997 (32-5) 1999 (26-1N)
• Sales: Singapore
• Fabrication: Singapore
• Service Base: Singapore
• Host Type: Platform
• Contract Type: EPC

Project Characteristics

• No. Trees: 3 (32-5)
• 1 (26-1N)
• Water Depth: 120 m (390 ft)
• Tree Type: Horizontal
• Tree Pressure: 5,000 psi
• Tree Bore Size: 4"x2"
• Hydrocarbon: Oil

Project Ownership

• CNOOC 51%
• ChevronTexaco 33%
• ENI 16%

Scope of Work

32-5:

• Three (3) horizontal 4"x2" 5,000 psi subsea trees
• 18-3/4"x 5-1/2" concentric metal sealing tubing hanger with overtrawlable protective structure
• Electro-hydraulic subsea control system

26-1N:

• One (1) horizontal 4"x2" 5,000 psi subsea tree
• One (1) UWD-C subsea wellhead system
• Electro-hydraulic control system with topside control for both fields on HZ-26 platform
• Subsea umbilical termination unit and in-field control jumpers
• Installation tools and installation workover control system
• System integration testing, installation assistance, service and maintenance

Comments

The two (2) fields are 4 km (2.5 miles) and 8 km (5 miles) away from the host platform HZ-26. The HZ-32-5 Field consists of three (3) horizontal subsea trees, each with a completion guidebase and produce via dedicated production flowline. The flowlines are interconnected to allow pigging through all three (3) wells. The HZ-26-1N Field consists of one (1) horizontal subsea tree and completion guidebase with flushing loop.

Both fields are controlled from and producing to their host platform. The control system on the host platform will allow the addition of four (4) other wells should the need arise. Gas produced from CACT’s network of fields is used for gas-lifting the HZ-32-5 and HZ-26-1N wells.