Engineered LCM Design Yields Novel Activating Material for Potential Application in Severe Lost Circulation Scenarios

IADC/SPE Drilling Conference and Exhibition

Whitfill

Jamison

et al. 2014

Self Cite

With increased drilling activity in deeper, harsher, and more complex environments, controlling non-productive time (NPT) during drilling is critical to lowering the cost of well construction. Lost circulation (LC), one of the main contributors to NPT, is a widely discussed topic drawing industry attention, as is evident from recent publications and forums/workshops on the topic. The literature on LC reveals several means of mitigation, ranging from the simple use of Lost Circulation Materials (LCMs) to the use of gunk/chemical sealants and methods for altering near-wellbore stresses (stress caging or wellbore strengthening). There is a subtle difference between lost circulation and wellbore strengthening, and any research should help facilitate a better understanding of the two.Presented previously (Kumar et al. 2010;Savari et al. 2012) were novel insights into LCMs for wellbore strengthening applications. Continuing the research effort, this paper discusses another approach for designing LCMs to withstand higher wellbore pressures within a fracture. A property of Plug Breaking Pressure (PBP) was determined for different LCM combinations using a permeability plugging apparatus (PPA) with tapered slots. LCM combinations with differing mechanical properties behaved differently when compared using the PBP data. Particles, such as ground marble (GM), alone were not able to plug the tapered slot and hence the PBP was zero. Based on the previous work described by Savari et al. (2012), the addition of resilient graphitic carbon helped with plugging the tapered slot, with a PBP of approximately 900 psi. Adding fibers to the LCM combination was also evaluated. Plugging did not improve when fibers were added just to one other type of particulate LCM. But, the combination of ground marble, resilient graphitic carbon, and specific fibers was found to provide the most efficient plugging with the highest PBP of approximately 2,100 psi.This work confirms that all LCMs are not equal and that the LCM type plays a role in terms of both plugging and "toughness" that better withstands displacement pressures. It also validates that, most of the time, combinations of LCM work more effectively compared to using just one type alone. The novel PBP data on different LCM combinations can provide a qualitative comparison of their ability to withstand displacement and/or failure pressures when designing LCM combinations in wellbore strengthening applications.

Section: Introductionmentioning

confidence: 99%

A Method to Evaluate Lost Circulation Materials—Investigation of Effective Wellbore Strengthening Applications

IADC/SPE Drilling Conference and Exhibition

Whitfill

Jamison

et al. 2014

Self Cite

“…This has led both the service providers and operators to examine unconventional LCMs that might be capable of working in severe lost circulation situations. Earlier works (Kumar et al 2010Miller et al 2013;Savari et al 2011Savari et al , 2013a) present the novel concepts in terms of examining different properties of LCMs and improvised methods and tools for testing LCMs, and they also discuss some unconventional LCM combinations. This paper also discusses a novel or unconventional LCM (chemical sealant) that has the potential to arrest or mitigate severe-to-total fluid losses in production zones.…”

Section: Introductionmentioning

confidence: 99%

Reservoir Friendly Rigid Setting Fluid Arrests Lost Circulation While Minimizing Reservoir Damage

SPE International Symposium and Exhibition on Formation Damage Control

Whitfill

Miller

2014

Self Cite

Currently, many producing formations are carbonates and/or depleted sands that are characterized by highly permeable flow paths or vugs. Severe-to-total loss of drilling fluid in these formations is a major concern from both the drilling and reservoir damage perspectives. Conventional particulate lost circulation materials (LCMs), such as acid-soluble ground marble, might not effectively cure severe losses. Furthermore, because the application is in a producing formation, avoiding reservoir damage is a major criterion that any potential solution should satisfy. The "band-width" of available solutions that are both efficient and reservoir friendly is narrow, leading to both high cost and potentially risky drilling practices.A possible solution is using an acid-soluble right-angle-setting composition (RAS-Co) that was developed to provide the industry with a more efficient solution for plugging and isolating producing zones that have high drilling fluid loss rates. RAS-Co is formulated from inorganic, nonhazardous powders and fluids mixed in fresh water or seawater. RAS-Co is engineered to be a low-viscosity (18 to 30 cp) fluid containing small particulates, which allows it to be mixed at the rigsite and pumped through any drillstring configuration. It is designed to react at a specific bottomhole circulating temperature (BHCT) in a consistent and controllable manner with a "right-angle" set. Once it is spotted/placed in the suspected loss zone, it helps eliminate further fluid losses and formation damage. The small particle size distribution acts as a pore-bridging material while in the fluid state, and the right-angle-set characteristic makes the material non-invasive to the formation and allows it to be easily drilled or removed with acid. It can be used in zones with up to 300°F circulating temperature and tolerates up to 50% contamination with water or drilling fluids. This paper describes attributes of RAS-Co along with successful field applications that illustrate it is an effective solution for controlling reservoir damage by helping to stop severe lost circulation events.

“…The literature on LC reveals several means of mitigation, ranging from the simple use of lost-circulation materials (LCMs) to the use of gunk/chemical sealants and methods for altering near-wellbore stresses (stress caging or wellbore strengthening). There is a subtle difference between LC and wellbore strengthening, and any research should help facilitate a better understanding of the two.Presented previously (Kumar et al 2010;Savari et al 2012) were novel insights into LCMs for wellbore-strengthening applications. Continuing the research effort, this paper discusses another approach for designing LCMs to withstand higher wellbore pressures within a fracture.…”

mentioning

confidence: 99%

“…Particles, such as ground marble, alone were not able to plug the tapered slot, and hence the PBP was zero. By use of the previous work described by Savari et al (2012), the addition of resilient graphitic carbon (RCG) helped with plugging the tapered slot, with a PBP of approximately 900 psi. Adding fibers to the LCM combination was also evaluated.…”

mentioning

confidence: 99%

See 1 more Smart Citation

A Method To Evaluate Lost-Circulation Materials—Investigation of Effective Wellbore-Strengthening Applications

SPE Drilling &Amp; Completion

Whiftill

Jamison

et al. 2014

Self Cite

With increased drilling activity in deeper, harsher, and more-complex environments, controlling nonproductive time during drilling is critical to lowering the cost of well construction. Lost circulation (LC), one of the main contributors to nonproductive time, is a widely discussed topic drawing industry attention, as is evident from recent publications and forums/workshops on the topic. The literature on LC reveals several means of mitigation, ranging from the simple use of lost-circulation materials (LCMs) to the use of gunk/chemical sealants and methods for altering near-wellbore stresses (stress caging or wellbore strengthening). There is a subtle difference between LC and wellbore strengthening, and any research should help facilitate a better understanding of the two.Presented previously (Kumar et al. 2010;Savari et al. 2012) were novel insights into LCMs for wellbore-strengthening applications. Continuing the research effort, this paper discusses another approach for designing LCMs to withstand higher wellbore pressures within a fracture. A property of plug-breaking pressure (PBP) was determined for different LCM combinations by use of a permeability-plugging apparatus (PPA) with tapered slots. LCM combinations with differing mechanical properties behaved differently compared with PBP data. Particles, such as ground marble, alone were not able to plug the tapered slot, and hence the PBP was zero. By use of the previous work described by Savari et al. (2012), the addition of resilient graphitic carbon (RCG) helped with plugging the tapered slot, with a PBP of approximately 900 psi. Adding fibers to the LCM combination was also evaluated. Plugging did not improve when fibers were added only to one other type of particulate LCM. But, the combination of ground marble, RGC, and specific fibers was found to provide the most-efficient plugging, with the highest PBP of approximately 2,100 psi.This work confirms that all LCMs are not equal and that the LCM type plays a role in terms of both plugging and "toughness" to better withstand displacement pressures. It also validates that, most of the time, combinations of LCMs work more effectively compared with the use of only one type. The novel PBP data on different LCM combinations can provide a qualitative comparison of their ability to withstand displacement and/or failure pressures when designing LCM combinations in wellbore-strengthening applications.