Energy Policy Act of 2005 (Ultra-deepwater and Unconventional Resources Program)
A 1,000 Level Drill Pipe Deployed Fiber Optic 3C Receiver Array for Deep Boreholes
US Sensor Systems, Inc.
Premier Drill Pipe, LTD
In the U.S. Ultra-Deepwater (UDW) part of Gulf Of Mexico (GOM), very large oil and gas resources are found in complex geologic formations under regionally extensive thick salt layers. It has proved extremely difficult to record the good quality seismic data using standard surface seismic techniques that is required to map the oil and gas resources in sufficient detail to both find and efficiently produce these resources. The high pressure and hot well environment in the very deep wells drilled to explore for and produce the oil and gas in the GOM UDW has posed a tremendous challenge for using borehole seismic techniques as well. Combining the poor surface seismic data, the small amount of borehole seismic data and the sparse appraisal wells has in combination led to a poor understanding of the reservoirs which has resulted in that many wells and fields have underperformed. It is the objective of this project to demonstrate that UDW GOM oil and gas resources can be efficiently mapped and recovered by applying advanced mapping and monitoring techniques on the large volumes of borehole seismic data that can be recorded using ultra long borehole seismic receiver arrays that have been designed to operate in the extreme environment of the UDW GOM wells.
Description of the Project
It has been shown that borehole seismology is technically able to map and monitor complex reservoirs in areas where surface seismic has failed to record any useful data at all. Currently borehole seismic techniques are limited in their use for mapping and monitoring oil and gas reservoirs in UDW GOM by the limited number of receivers deployable in very deep wells and their limited ability to operate at high temperatures and high pressures.
To meet the objectives of high resolution imaging and monitoring of UDW reservoirs which is required to reduce the exploration and development risk and to improve the production, this project will develop a 1,000 level drill pipe deployed borehole seismic receiver array system using fiber optic sensor technology and build a 100 level demonstration system operational to 30,000 ft in a GOM UDW well. The fiber optic sensor technology was developed by the US Navy for its submarine fleet and it has been shown that the fiber optic sensors are more sensitive, have a lower noise floor and are more robust than electronic equivalents such as hydrophones, geophones and MEMS sensors. These attributes are making them excellent candidates for the demanding borehole environment. The drill pipe deployment design allows the receiver array to be deployed in both vertical and horizontal wells which is an operational requirement in GOM since many of the wells in GOM are highly deviated. The all metal clamping system of the geophone pods is using drill pipe hydraulics as a power source. The fiber optic receivers are operated using light only and manufactured using high temperature fibers. This combination will allow the design and manufacturing of receiver arrays that can operate to temperatures up to 300ºC (572ºF) at pressures up to 30,000 psi since no electronics or electric power will be used in either the hydraulic clamping system or for the fiber optic geophones. Since no electronics or electric equipment is part of the borehole component of the borehole seismic imaging system, the system will be extremely robust and can thus be used for long term monitoring using redeployable borehole seismic systems or for permanent installations in boreholes.
A 100 level borehole seismic demonstration system capable of 1,000 levels available to the UDW GOM operators that can operate in both vertical and horizontal wells at pressures up to 30,000 psi and at temperatures up to 300ºC (572ºF). A borehole seismic survey will also be recorded with the 100 level array to demonstrate the capabilities of the borehole seismic system. This survey will record both 3DVSP data and micro seismic data and the data will be processed.
Commercial Applications and Other Benefits from the Proposed Project
High resolution 3D images derived from high frequency high fidelity large volume borehole seismic P and S wave data will be critical to understand the geometry and dynamics of complex reservoirs in UDW part of GOM. These images lower the risk of misplacing new wells and redrilling existing wells into the reservoirs and will together lead to a greatly improved recovery of the oil and gas resources. Improved understanding and delineation of reservoirs lowers the economic risk, allowing for the operation of smaller, more complex and normally marginal oil and gas fields. It will also allow for the identification and production of previously unknown oil and gas resources in larger fields such as in blocks isolated by faulting and stratigraphy.
Partners and Subcontractors
In addition to Paulsson Inc. the following five companies will participate and contribute to the statement of work; US Sensor Systems, Inc., Optiphase, Inc., Kemlon Products, Premier Drill Pipe, Ltd. and Norsar.
Principal Investigator: Björn N.P. Paulsson, Ph.D