DI-86 – Seismic while Drilling for Enhanced Look-Ahead-of-Bit Capabilities

DI-86     Seismic while Drilling for Enhanced Look-Ahead-of-Bit Capabilities – – Department of Energy / Industry Program for Drilling Optimization

Date Submitted: July 14, 1999
Technical Area: Production
Title: Seismic while Drilling for Enhanced Look-Ahead-of-Bit Capabilities – Department of Energy / INEEL / Industry Program for Drilling Optimization
Submitted by: TerraTek, Inc. Arnis Judzis, Vice President 400 Wakara Way Salt Lake City, UT 84108 (801) 584-2400
Principal Investigator(s): TerraTek, Inc. Alan Black (ablack@terratek.com) and Idaho National Engineering and Environmental Laboratory Tim Green (tsg@inel.gov)
Business Impact: This program is designed to improve the efficiency and safety of drilling operations through the development and deployment of a down hole seismic source for enhanced ‘look-ahead-of-the-bit’ capabilities while drilling. The broad based expertise of the Idaho National Engineering and Environmental Laboratory (INEEL), Lawrence Berkeley National Laboratory (LBNL) and full scale testing facilities available at TerraTek, Inc. offer a unique opportunity to provide operators and drilling contractors with a means to improve well safety and economics. This program is past the conceptual design phase and is heavily leveraged through ongoing DOE / INEEL research. The successful completion of this program will provide drilling risk mitigation through the provision of a down-hole hydraulic seismic source with the capability of providing real time geologic information ahead of the bit that can be used for pore pressure prediction, casing seat depth selection, and geological prognosis. Accurate prediction of formation pressures (pore pressures) is critical to conduct safe and economic drilling operations. This information is essential for both optimizing casing and drilling fluid programs, and is vital in avoiding well control problems. Conventional pore-pressure prediction techniques at the well site typically relate measured porosity indicators (velocity, resistivity, density) and real-time drilling parameters (drill rate, bit torque, formation gas, shale density). While effective in predicting pore pressures at the depth the data is being collected and allowing for some prediction of pore pressure to be made ahead of the bit based on trend analysis, this method does not provide true “look ahead” capability. Additionally, in areas lacking sufficient well control information and in deep water where there is little margin between fracture gradients and pore pressure, a more quantitative method is required in order to meet exploration objectives in a safe and cost effective manner. Seismic while drilling techniques offer improved safety and drilling performance for areas where uncertainties exist in formation tops and prediction of over-pressured zones. Operations in deep offshore waters are an example where benefits may be derived from enhance ‘look ahead’ capabilities. Examples of potential economic benefit include elimination of casing strings, maintenance of optimum hole size to total depth, and reduction of “trouble time” related to lost circulation, stuck pipe, and managing kicks.
Technical Objectives: The project proposes a two-year program to develop a down-hole hydraulic seismic source. Operational requirements of the down-hole source will include 1) capability of being used continuously during normal drilling operations, 2) meet industry reliability requirements for down-hole tools, and 3) produce a seismic signal capable of resolving pore pressures to within 0.5 ppg 1,000 to 1,500 feet ahead of the bit.
Methodology: The work is being proposed in three Phases. The first phase will consist of the development of an appropriate protocol for scale testing the hydraulic source and numerical models for signal response and evaluation. Additionally, a prototype tool will be developed based on using the hydraulic force of the mud as a seismic source. The second phase of the project will involve the fabrication of a hardened tool and the performance of field tests. The final phase will conduct any additional field testing required for licensing of the technology for commercial development. In order to field test the system it will be necessary to have access to an industry test well and an appropriate receiver system. Specific tasks of the three phases of the project are detailed below. Phase 1 1. Develop system/protocol for testing down-hole hydraulic seismic source. 2. Develop acoustic coupling/signal models for evaluation of down-hole hydraulic seismic source. 3. Evaluate hydraulic coupling. 4. Design/construct/test bench scale hydraulic valve. Phase 2 1. Design/construct field-hardened prototype hydraulic valve. 2. Field-test prototype in onshore Gulf Coast well. Phase 3 1. Additional field tests and commercialization of the tool.
Deliverables: The primary deliverable of this project will be a prototype down-hole seismic source that can be run with the drill string for the purpose of providing look ahead pore pressure prediction while drilling. This system will enable drilling operations to be conducted in a safer manner while providing geologic information ahead of the drill bit in real time. Specific deliverables will include: · Protocol for scale testing down-hole seismic source(s). · Numerical model for evaluating down-hole seismic sources. · Prototype bench scale down-hole seismic source (hydraulic valve). · Evaluation report on bench scale tests conducted with prototype. · Field hardened down-hole seismic source (hydraulic valve). · Report on initial field evaluations of down-hole seismic source. · Report on final field tests of down-hole seismic source. · Commercial license.
Startup Date: Project was initiated May ’99 with Department of Energy funding. Anticipated start-up for JIP is November 1, 1999.
Project Duration: 2 years
Project Cost: $250,000
Cost per Participant: $50,000 (Assuming 5 participants. In kind support will be determined during scoping meetings)
Comments: The Department of Energy has provided $225K for FY 99. FY 00 funding is anticipated at the same level.