Details

Project TitleSmart Expandable Loss Circulation Materials
Track CodeLSU-2015-046
Short Description

Shape memory polymers (SMPs) are a new type of loss circulation material (LCM) that expand to prevent drilling fluid loss into rock formation fractures during the well-drilling process, reducing risk of complications such as formation kick. The SMPs maintain their beginning size until activated by the high temperatures inside a rock formation fissure, where they then expand to 10-60% of their initial diameter. Once expanded, the SMPs will stay in this expanded state despite subsequent temperature changes.

During the process of shape recovery, pressure released from the SMPs act on fracture surfaces and increase circumferential stress in the rock formation, strengthening it. The wellbore can now sustain higher mudweight, reducing the risk of fluid influx from the surrounding rock and subsequent formation kick. SMPs can be mixed with other loss circulation material or used on their own.

Abstract

A lost circulation incident can have a heavy financial cost in the form of losing rig time, mud fluid and in severe cases well blowout with serious consequences. Hence, considerable research and experiments have been done to make lost circulation materials that can seal fractures effectively. However, lost circulation materials used today still have limitations such as damaging production zones, plugging tools such as LWD and in worst cases totally failing in sealing the fractures and causing a well to be drilled with total loss. In this work, we introduce a new class of “Smart Lost Circulation Materials (LCMs)” to seal the fractures efficiently without damaging production zones or plugging tools. Our smart LCMs are made out of thermoset shape memory polymers which are activated by the formation’s in situ temperature to effectively seal the fracture while providing extra compressional forces to strengthen the wellbore. A fully coupled fluid flow and particles model is developed to study the effectiveness of smart LCMs and evaluate their sealing efficiency via different combinations and size distributions. In addition, a series of experiments were conducted using particle-plugging apparatus (PPA) to measure the sealing efficiency of the smart LCMs. The proposed LCM shows promising results in quick and effective sealing of fractures and building stress.

 
TagsNone
 
Posted DateJun 26, 2017 10:51 AM

Benefits

  • Reduction of non-productive time
  • Reduced well construction costs caused by mud loss, which is responsible for $2 - $4 B in costs annually
  • Reduced risk of formation kick and blowout
  • Reduced risk of damage to the drill string and wellbore

Applications

  • Down-hole drilling
  • Oil and gas recovery

Licensing Contact

Files

File Name Description
LSU-2015-046 Tech Summary Smart Expandable Loss Circulation Materials Download
Smart Expandable LCMs - A Theoreticl and Experimental Study Research Manuscript Download

Intellectual Property

Patent Number Issue Date Type Country of Filing
Patent Pending None Provisional United States