Session: 04-01-02 Leak Detection and Monitoring - Part II

Paper Number: 87311

87311 - An All Optical Multi-Sensor Well Monitoring System to Secure Gas Storage Operations 

Paulsson, Inc. (PI) has partnered with Pacific Gas & Electric (PG&E) and California Energy Commission (CEC) funded by the CEC grant PIR-19-001, to develop and apply cost-effective, all-optical Underground Gas Storage (UGS) reservoir surveying and monitoring technologies to make underground gas storage safe, efficient, and economical. The project goals and objectives includes designing, prototyping, third party laboratory testing, building and installing a borehole all optical multi-sensor array into a well drilled at UGS facility. The installed all-optical multi-sensor array includes Enhanced Distributed Acoustic Sensors (EDAS), and Distributed Temperature Sensors (DTS). The multi-sensor array was deployed in a well to a measured depth of 5,400 ft at the McDonald Island Underground Gas Storage (UGS) facility near Stockton, CA. The McDonald Island facility is the 9^th largest UGS in the USA and supplies Natural Gas to Northern California. We deployed the multi-sensor array on the 4.5” production tubulars placed and centralized inside the 8 5/8” casing. The sensor array will be used to record data allowing the development of a dynamic reservoir model using active and passive seismic data. The field data will allow development of new processing technologies including building a highly accurate velocity model. The data from the 2,000 acoustic sensors spaced 3 ft and the 1,000 temperature sensors spaced 6 ft will also be used to image and characterize faults in the gas storage field using interferometric fault imaging. The passive sound data from gas flow will allow the mapping of the flow paths and the effective areas of gas injection and storage. After the installation in July 2021 the optical sensor system has been continuously operated and monitored. While the data is being recorded the data is field processed in real time using remote access to the field data acquisition system.

We will deploy the all-optical array for a period of at least 6 months and monitor the gas storage field around the well bore for injection and production gas flows, casing leaks, and geologic deformation due to faults. This processing includes interpretation and report on results as well as provide recommendations for cost-effective UGS monitoring and safe-guarding. We will develop fit-for-purpose processing technologies, including Machine Learning, which will allow rapid processing of recorded, acoustic, and temperature data. We will process, interpret, and report on the data collected. We will develop a velocity model of the gas storage field to map the location of the acoustic events. We will map the faults and map gas storage sands using interferometric fault imaging.

There are several keys to high resolution imaging and long-term, precise monitoring. The first requirement is that appropriate sensors that can record relevant data are deployed. The second is that the spatial location of these sensors are precisely known. We deployed the large aperture, 5,400 ft long, sensor array using regular production tubulars. This pipe has well defined and precisely characterized elastic and temperature elongation parameters allowing an exact determination where the sensors are located. We will use our data and experience to design and deploy more advanced arrays of optical sensors, including pressure, strain, and chemical sensors suitable to be deployed long term in gas storage wells.

The optical sensor system has recorded a number of nearby small earthquakes which has provided the seismic sources that will be used for site characterization. The array will be used to characterize and monitor the gas injection and withdrawal for a number of months. The final goal is to develop a range of commercial services that can immediately be utilized by all UGS companies.

Presenting Author: Bjorn Paulsson Paulsson, Inc.

Presenting Author Biography: Dr. Bj&#246;rn N.P. Paulsson, CEO &amp; President<br/>Paulsson, Inc.<br/>E-mail: bjorn.paulsson@paulsson.com, Direct Line/Mobile: 310-780-2219<br/><br/>Dr. Paulsson has developed time- lapse seismic monitoring techniques to characterize and monitor rockmasses for CCUS, UGS, EGS and EOR applications. Performed the industry first time lapse tomographic monitoring survey of a fractured rock mass 1978 – 1980. He currently holds nine patents, with one patent pending, and has published over 60 papers and reports. He led large research projects while at Chevron and started and managed high technology seismic companies. During his career, he has developed new high temperature borehole seismic source and receiver technologies.<br/>Education<br/>University of California, Berkeley, Ph.D., Engineering Geophysics, 1983 <br/>University of California, Berkeley, M.S., Engineering Geophysics, 1979 <br/>University of Gothenburg, Sweden, Fil. Kand., Geology, 1976<br/>Qualifications<br/>Founder of borehole seismic service companies. Extensive experience organizing and managing large multi-company research projects. Inventor of equipment for borehole seismology. Author of more than 60 papers, nine patents and one patent application.<br/>Experience<br/>CEO &amp; President, 4/2009 – Present, Paulsson, Inc. Formed Paulsson, Inc. to develop advanced high temperature borehole seismic technologies using all optical sensors.<br/>CEO &amp; President, 3/97 – 4/2009, Paulsson Geophysical Services, Inc. (P/GSI). Formed Paulsson Geophysical Services, Inc. to commercialize a downhole seismic source developed with CRADA funding from US DOE, GRI, four oil companies and two manufacturing companies. Designed and built the 400 level 3C downhole seismic receiver array. Conducted the largest VSP surveys in the oil and gas industry.<br/>Senior Research Geophysicist, 4/84 - 3/97, Chevron Petroleum Technology Company. Proposed, organized and managed a $12 million project to develop a downhole seismic source for borehole seismology. PI of several Chevron projects. Initiated new research at COFRC/CPTC in the field of borehole geophysics and oil reservoir characterization using new borehole seismic techniques. Developed tomographic offshore VSP techniques.<br/>Research Engineer, 1/83 - 3/84, Dep. of Material Science and Mineral Eng., U. of California, Berkeley, CA 94720. Worked on designing and performing an ultrasonic velocity and attenuation laboratory-monitoring program of rock samples during tensile fracturing.<br/>Staff Scientist, 6/77 - 8/81, Lawrence Berkeley Laboratory, Earth Science Division. Planned, proposed, and conducted a research project to develop ultrasonic crosshole techniques for determining physical properties of in-situ rock masses. Executed experiments in the field and laboratory to acquire data. Developed processing techniques to correlate changes in observed data with changing rock properties due to temperature, stress, and fracture permeability.