EXPERIMENTAL

Two days of drilling stand testing of the Pressure Coring System (PCS) with three new cutting shoes were conducted using Texas Cream Limestone drilling samples, at the facilities of Mauer Engineering in Houston, TX during mid-November, 2001. These tests were successful and provided information about RPM, flow rate, and weight-on-bit (WOB) for each cutting shoe tested.

Design for PCS Gas Manifold will be finalized so that parts can be procured for assembly prior to Leg 201. Dr. Gerald Dickens (Rice University) will work with JOI to define the necessary components of this manifold. The PCS tool and manifold will be shipped to San Diego and placed onboard the JOIDES Resolution during portcall in late January, 2002. These activities are included in Task 2.0 of the DOE/NETL Cooperative Agreement with JOI.

The Davis-Villinger Temperature Probe (DVTP), Davis-Villinger Temperature Probe with Pressure (DVTP-P) and other ODP memory tools will be shipped to San Diego and placed onboard vessel during portcall for use on ODP Leg 201 (Task 3.0).

Selection and purchase of Infra-Red Thermal Imaging System (IR-TIS) is underway for delivery in mid-January, 2002 (Task 4.0). JOI will designate the appropriate staff members to be trained in mid-January, 2002 to operate the IR-TIS during ODP Leg 201. Discussions are ongoing between ODP engineers and LDEO logging staff scientists related to the specifics of LWD and VSP experiments planned for ODP Leg 204 (Task 5.0). Preliminary technical discussions have been ongoing since early December 2001 to define the scope of this activity. (Tom Pettigrew, Mike Storms, ODP/TAMU engineers; Greg Myers, LDEO contact). Some tool modifications may be required to integrate ODP sample chambers with the Resistivity-at-bit (RAB) LWD tool

During this period, discussions were initiated with FUGRO (Task 6.0) to negotiate a sub-recipient

Statement of Work for modifying their Piezoprobe tool for testing onboard the JOIDES Resolution during ODP Leg 204. Technical and operational issues related to the use of this tool are being explored. A Go-no-Go decision for this project will be made by JOI in early-March, 2003, once time and operational schedules for ODP Leg 204 are better defined.

RESULTS AND DISCUSSION

The “Preliminary Evaluation of Existing Pressure/Temperature Coring Systems” report was successfully completed and delivered to DOE/NETL on October 22, 2001 to fulfill the obligations under Task 1.1 of the Cooperative Agreement (Rack, 2001). DOE/NETL Program Manager William Gwilliam provided “go” decision for development of improvements to the ODP Pressure Coring System (PCS) and PCS Gas Manifold. This report provides a prelimary evaluation of four existing coring devices, namely, the Ocean Drilling Program (ODP) Pressure Core Sampler (PCS), the HYACE Rotary Corer (HRC), the FUGRO Pressure Corer (FPC), and the Japanese Pressure Temperature Core Sampler (PTCS). Each of these four systems are wireline retrievable and are designed to recover sediment, fluids, and gas at near in-situ pressures in the sub-seafloor. There are two existing PCS tools at present and one prototype tool for each of the HYACE systems (i.e., HRC and FPC), plus four existing PTCS tools, to the best of this author’s knowledge. These four coring devices share a common early development history in the Pressure Core Barrel (PCB) development of the Deep Sea Drilling Project (DSDP) and the subsequent development of the PCS by ODP since 1986.

International engineers representing the future HYACE and the Japanese PTCS development teams, who participated in ODP Leg 164 onboard the D/V JOIDES, gained valuable experience and operational insights from the intensive scientific deployments of the ODP Pressure Core Sampler prior to the start of these other projects.

The PCS is a wireline retrievable rotary pressure corer, which is driven by the rotation provided by the top drive mounted in the derrick of the D/V JOIDES Resolution. This system can also be used as a push corer without rotation.

The PCS has been used on ODP legs in a wide range of deepwater. Moderate modifications to the PCS were made prior to the deployments on ODP Leg 164 which resulted in extensive use of the PCS and gas manifold modifications. Discussions about the PCS design and potential modifications to improve its use have continued.

During ODP Leg 164 on Blake Ridge and Carolina Rise the PCS was successfully deployed on 46 runs to recover core samples at near in-situ pressures up to 5205 psi/355 bars. The PCS was instrumental in providing estimates of in situ gas concentrations and compositional analyses that resulted in revised estimates for the volume of gas contained in gas hydrate reservoirs in the subsurface of Blake Ridge (Dickens, et. al., 2000). The PCS has not been used extensively since Leg 164, but minor upgrades and testing are planned for ODP Leg 201 (Peru Margin; January 28 through April 1, 2002), followed by operational use of the tool on ODP Leg 204 (Oregon Margin, Hydrate Ridge; July 8 through September 6, 2002). The PCS is considered an operational tool by ODP. The primary issues to be addressed in time for ODP Leg 201 are modifications to the PCS bit design, better weight-on-bit (WOB) control, reduced maintenance and turn around time, and improved quality of fluid sampling.

The HYACE Rotary Corer (HRC) and FUGRO Pressure Corer (FPC) tools have been developed through a European Union (EU) research project known as HYACE, or "HYdrate Autoclave Coring Equipment", which existed from late 1997 until March 2001. The HRC, has been designed to be a wireline retrievable, rotary coring tool driven by a downhole inverse moineau motor. The FPC is designed to be a wireline retrievable push and percussion corer driven by a hydraulic hammer that evolved originally from a Russian design. Both of these tools are prototype systems, meaning that there is only one of each available for testing. The other parts of the "complete" HYACE system are (1) the Laboratory Transfer Chamber (LTC) and the GEOTEK vertical LTC Logger. These two systems are planned to be available for testing during ODP Leg 204. An extension to the HYACE project was granted by the EU program managers (i.e., from September 2000) to allow the field testing on ODP Leg 194 to take place in early 2001.

The HRC and FPC were each deployed four times in test runs during ODP Leg 194. Progress was made in learning about the handling requirements for these tools onboard the D/V JOIDES Resolution and in providing experience with the operation of these prototype tools. A total of 72 hours was allocated to the testing of these HYACE tools. During Leg 194, two holes (i.e., Hole 1192A = 242 mbsf (meters below sea floor) Total Depth (TD); Hole 1192B = 240 mbsf TD) were drilled in 385 m and 374 m of water depth, respectively.

The FPC was used three times in Hole 1192 A, at 28.5 mbsf (push mode), 86.5 mbsf (percussion mode), and 192 mbsf (percussion mode) and in Hole 1192B at 179.9 mbsf. The HRC was used twice in Hole 1192A, at 231 mbsf and 241.4 mbsf, and twice in Hole 1192B, at 180.9 mbsf and 335.2 mbsf. The autoclave (pressure chamber) on the FPC was only able to hold pressure (42 bar; 617 psi) during one of the four tool deployments. The HRC recovered one 35 cm-long core out of the four runs and had a variety of operational problems. Concern was expressed by the ODP engineers about the difficulty in handling and assembling the tools on the rig floor, as well as the potential weakness of the flapper valve used in the HYACE tool design. FUGRO and HYACE engineering teams plan to provide a more robust flapper hinge in future versions of these tools and to address other perceived design flaws. Bending stresses on both of the tools were reduced by the fabrication of supports onboard the drillship by the core techs and drilling engineers; the HRC had difficulty latching into the extended core barrel (XCB) bottom hole assembly (BHA). Other modifications to the handling and operational plan were crafted in real time during testing operations on ODP Leg 194.

CONCLUSION

The PCS, FPC, and HRC can be operated with the standard bottom hole assembly of the ODP APC/XCB systems (with some minor modification of the HYACE/HYACINTH tools). The Japanese PTCS requirement for larger pipe diameter make its use by ODP at present unlikely; however, this system may find a role in the future Integrated Ocean Drilling Program (IODP) after October 1, 2003.

LIST OF ACRONYMS AND ABBREVIATIONS

APC - Advanced Piston Corer;
BHA - Bottom Hole Assembly;
DOE - Department of Energy;
DSDP - Deep Sea Drilling Program;
DVTP - Davis Villinger Temperature Probe;
DVTPP - Davis Villinger Temperature Probe with Pressure;
EU - European Union;
FPC - Fugro Pressure Corer;
HRC - HYACE Rotary Corer;
HYACE - Hydrate Autoclave Coring Equipment;
HYACINTH - Deployment of HYACE tools In New Tests on Hydrates;
IODP - Integrated Ocean Drilling Program;
IR-TIS - Infrared Thermal Imaging System;
JOI - Joint Oceanographic Institutions;
JOIDES - Joint Oceanographic Institutions for Deep Earth Sampling;
LDEO - Lamont Doherty Earth Observatory (Columbia University);
LTC - Laboratory Transfer Chamber;
LWD - Logging While Drilling
MBSF - Meters Below Sea Floor;
NETL - National Energy Technology Laboratory;
NSF - National Science Foundation;
ODP - Ocean Drilling Program;
PCS - Pressure Coring System;
PSI - Pounds per Square Inch;
PTCS - Pressure Temperature Coring System;
RAB - Resistivity at the Bit;
R/V - Research Vessel;
TAMU - Texas A&M University;
TU - Technical University;
VSP - Vertical Seismic Profiling;
WOB - Weight on Bit;
XCB Extended Core Barrel.