(CLOSED) DOE-FOA-0002083 DOE EERE Subsurface Stress and Lost Circulation in Geothermal Drilling

Sponsor Name: 
DOE EERE
Amount: 
$7,000,000.00
Description of the Award: 

Background and Purpose:

The Geothermal Technologies Office (GTO), within the U.S. Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy (EERE), supports early-stage research and development (R&D) to strengthen the body of knowledge upon which industry can accelerate the development and deployment of innovative geothermal energy technologies.

GTO works to develop technologies to drive down the costs and risks of geothermal energy. Geothermal energy is a domestic energy resource from the heat of the earth, which represents a reliable, secure, clean, and nearly inexhaustible energy source. Figure 1 plots risks and costs as a function of the stage of development moving from early characterization to full power plant operations. In the geothermal power sector, risks are highest in the early stages of exploration (“pre-survey”) and exploratory (“test”) drilling, and costs begin to skyrocket once drilling has started.

Improved understanding of the stress state in geothermal fields, will lead to significant cost reductions at several stages of the development cycle, including improved drilling success rates and sustainability of reservoirs over time. Without prior knowledge of the subsurface stress, wells could be drilled in locations that don’t best access existing geothermal resources, limiting power production potential and expending resources in an already capital-poor industry.

Another challenge that can contribute to the high costs of geothermal development is the loss of fluids to surrounding rock during drilling, or lost circulation events. Because geothermal drilling operations tend to target zones of highly fractured and altered material, lost circulation is more common in geothermal drilling than in other applications and can represent 20% of the costs for exploratory wells and reservoir development.

Effective assessment of the subsurface stress and being able to mitigate and manage lost circulation events are critical to improving the efficiency of geothermal energy development and ultimately can play a major role in increasing domestic energy affordability. GTO therefore invites applications for early-stage R&D on the topics of subsurface state of stress and lost circulation as applied to geothermal exploration and drilling.

Technology Space and Strategic Goals

The subsurface stress state – defined as the force applied to a body that can result in deformation, or strain, and usually described in terms of magnitude per unit of area – is important to all subsurface energy activities and to geothermal energy development in particular. This is because stress state dictates the extent, orientation, and size of both man-made and naturally occurring fractures. Fracture networks provide the required permeability for a geothermal reservoir, so an understanding of the stress state is valuable for siting wells. Current capabilities to directly measure or infer the stress state are woefully inadequate, especially away from boreholes. Stress measurement is typically an expensive, invasive process that yields information at a single point. Extrapolating beyond the near-wellbore environment is especially difficult due to the variability in rock properties.

Improved understanding of the stress state in geothermal fields will lead to significant cost reductions at several stages of the development cycle. As demonstrated by recent GTO-sponsored R&D, knowledge of the stress state and fracture morphology feeds into the conceptual models that are used to site wells for exploration drilling; better inputs at this stage can therefore lead to improved drilling success rates. In later project phases, the subsurface stress state informs well designs, re-injection strategies, and mitigation programs for induced seismicity. It is also a primary input to the design of any well stimulation program that could be used at a hydrothermal site. New stress-related data acquisition and modeling in highly prospective geothermal fields, as well as novel measurement techniques that are broadly applicable in geothermal conditions, are therefore an important path to accelerating geothermal deployment in the U.S. and a key objective of this funding opportunity.

In addition to the importance of stress, lost circulation events (LCEs) during drilling are a significant concern during the development of geothermal resources. LCEs are defined as the loss of drilling fluids to the formation and occur when drilling fluids pumped from the rig through downhole drilling equipment to lubricate and cool the drill bit and remove drill cuttings are “lost” – flowing into one or more geological formations instead of returning to the surface to complete a circulation path. LCEs increase costs because drillers need to replace lost fluids, may find drilling tools getting stuck in the wellbore, or have trouble with during cementing operations. If improperly managed, LCEs can lead to uncontrolled flows from wells (well blowouts). This could result in significant and costly damage to drilling equipment and/or loss of life. Managing and mitigating the risks around this potential problem represents significant costs to drilling operations.

Lost circulation is estimated to cost the oil and gas drilling industry $1 billion per year in rig time, materials, and other financial resources3 and according to one study4, lost circulation added an estimated $185,000 to the cost of an average geothermal well. Because geothermal drilling operations tend to target zones of highly fractured and altered material, lost circulation is more common in geothermal drilling than in other applications. The time and material costs for lost circulation can represent 10% of the total well costs in a mature geothermal field, and can exceed 20% of the costs for exploratory wells and reservoir development. When LCEs become severe enough that the drilling fluid is unable to clean the hole, cuttings can build up on the bottom-hole assembly and cause the drill string to become permanently stuck. Geothermal wells have been abandoned prior to reaching target depth due to this occurrence, and this is among the most severe financial impacts of LCEs. Personnel safety can also be impacted: if lost circulation suddenly lowers the fluid level in the well, hot water or steam can enter the wellbore causing a dangerous loss of well control. Furthermore, if circulation is lost in the production zone, it may be difficult to cure or manage the lost circulation without compromising the well’s productivity. Finally, lost circulation can result in bad cement jobs that can lead to further issues down the road.

Improved technologies for understanding subsurface stress, as well as novel or improved means for dealing with LCEs, are therefore key to lowering the cost of accessing geothermal resources. With this funding opportunity, GTO is seeking to sponsor early-stage R&D that will advance the state of the art in each of these related areas.

Topic Areas

Topic 1: Development of technologies for characterizing, monitoring, and predicting state of stress for geothermal exploration and drilling

Projects will advance the state of the art with respect to understanding the state of stress in the subsurface. Investigations are sought that will focus on improved measurement and/or monitoring of changes in stress orientation and magnitude at scales ranging from borehole (~1m) to reservoir (~1-10km) scale. Successful projects will significantly reduce the uncertainty on in situ stress estimates in geothermal environments. This uncertainty reduction will aid in reducing the costs of reservoir exploration, wellfield construction, and managing the evolution of geothermal reservoirs.

Areas of interest include:

• Development of new or improved methods for characterizing, monitoring, and predicting the state of stress from surface or borehole data.

• Multi-scale modeling and simulation of reservoir behavior at well-characterized geothermal sites.

Topic 2: Development of new technologies for prediction and mitigation of lost circulation events (LCEs) in geothermal drilling

Projects will develop improved methods of predicting, monitoring, avoiding, and mitigating loss of circulation events in geothermal drilling. Successful projects will provide developers of geothermal resources with an improved scientific basis for mitigating LCEs during the geothermal well construction process. Improved materials and processes in mitigating LCEs will result in a significant lowering of the cost of geothermal resource development.

Areas of interest include:

• Development of new or improved methods for characterizing and predicting lost circulation events, including ‘look-ahead’ technologies to characterize the conditions ahead of an advancing drill bit and monitor for the onset of a lost circulation event, as well as methods for characterizing the exact nature of such an event for the purpose of planning an effective response.

• Development of new or improved downhole materials for treatment of lost circulation in geothermal drilling. This includes materials that can be added to the drilling fluid system to seal off trouble zones as well as improvements to the associated lost circulation material (LCM) delivery systems.

• Development of new or improved cementing systems that overcome the difficulties associated with cementing near lost circulation zones.

• Development of new or improved methods for mitigating the risks of drilling without cuttings return (drilling blind) due to loss of circulation.

• Development of new or improved drilling methods for mitigating against fluid losses when they are encountered, such as dual-tube e reverse circulation drilling, expandable tubular technology, casing while drilling, etc.

Cost Sharing

The cost share must be at least 20% of the total allowable costs for research and development projects (i.e., the sum of the Government share, including FFRDC costs if applicable, and the recipient share of allowable costs equals the total allowable cost of the project) and must come from non-federal sources unless otherwise allowed by law. (See 2 CFR 200.306 and 2 CFR 910.130 for the applicable cost sharing requirements.)

PLEASE NOTE: Section 108, “Short-Term Cost-Share Pilot Program” of the recently enacted Department of Energy Research and Innovation Act (RIA), Pub. L. 115-246 removes the minimum statutory cost share requirement for Institutions of Higher Education and Non-Profit Organizations for research and development for a two year pilot period. Nevertheless, RIA does not automatically change the cost share requirements as set forth in 2 CFR 910.130 of DOE’s financial assistance regulation without first amending the regulation. Therefore, until the regulation is updated and aligned with RIA or a cost share waiver is issued, DOE programs and Contracting Officers must adhere to the cost share requirements as set forth in 2 CFR 910.130 and the FOA.

Eligibility:

Penn State may only submit one Concept Paper and one Full Application for each topic area of this FOA. This limitation does not prohibit an applicant from collaborating on other applications (e.g., as a potential Subrecipient or partner) so long as the entity is only listed as the prime applicant on one Full Application submitted under this FOA.

EERE makes an independent assessment of each Concept Paper based on the criteria in Section V.A.i of the FOA. EERE will encourage a subset of applicants to submit Full Applications. An applicant who receives a “discouraged” notification may still submit a Full Application. EERE will review all eligible Full Applications. However, by discouraging the submission of a Full Application, EERE intends to convey its lack of programmatic interest in the proposed project in an effort to save the applicant the time and expense of preparing an application that is unlikely to be selected for award negotiations. Other applicants will be discouraged from submitting a Full Application.

You must notify the Limited Submissions Office with EERE notification since only one Full Application for each topic from Penn State may be submitted.

Limit (Number of applicants permitted per institution): 
2
Sponsor Final Deadline: 
Jun 07, 2019
Other Deadline Dates: 
04/26/2019 - concept paper deadline
OSVPR Application or NOI Instructions: 

Interested applicants should send the following documents in sequence in one PDF (Last Name_DOEEERE2083_2019) no later than 4:00 p.m. on the internal submission deadline:

  • Cover Page must include:

    • Project Title
    • Topic Area (Topic 1 or Topic 2)
    • The technical and business points of contact, names of all team member organizations
  • Technology Description (1-page maximum) to include:

    • The proposed technology, including its basic operating principles and how it is unique and innovative;
    • The proposed technology’s target level of performance (applicants should provide technical data or other support to show how the proposed target could be met);
    • The current state-of-the-art in the relevant field and application, including key shortcomings, limitations, and challenges;
    • The data sources that will be used in the project
    • How the proposed technology will overcome the shortcomings, limitations, and challenges in the relevant field and application;
    • The potential impact that the proposed project would have on the relevant field and application;
    • The key technical risks/issues associated with the proposed technology development plan; and
    • The impact that EERE funding would have on the proposed project.
  • Addendum (1-page maximum) Describe succinctly the qualifications, experience, and capabilities of the proposed Project Team, including:

    • Whether the Principal Investigator (PI) and Project Team have the skill and expertise needed to successfully execute the project plan;
    • Whether the applicant has prior experience which demonstrates an ability to perform tasks of similar risk and complexity;
    • Whether the applicant has worked together with its teaming partners on prior projects or programs; and
    • Whether the applicant has adequate access to equipment and facilities necessary to accomplish the effort and/or clearly explain how it intends to obtain access to the necessary equipment and facilities.

Applicants may provide graphs, charts, or other data to supplement their Technology Description.

  • Formatting Guidelines and Page Limit:

    • Font/size: Times New Roman (12 pt.)
    • Document margins: 1.0” (top, bottom, left and right)
    • Standard paper size (8 ½” x 11)
To be considered as a Penn State institutional nominee, please submit a notice of intent by the date provided directly below.
This limited submission is in downselect: 
Penn State may only submit a specific number of proposals to this funding opportunity. The number of NOIs received require that an internal competition take place, thus, a downselect process has commenced. No Penn State researchers may apply to this opportunity outside of this downselect process. To apply for this limited submission, please use this link:
OSVPR Downselect Deadline: 
Wednesday, April 10, 2019 - 4:00pm
Notes: 
Topic 1 - Derek Elsworth (EME, EMS) and Topic 2 - Amin Mehrabian (EME, EMS) 4/15/19