Loss Prevention and Treatment
Lost circulation is one of the largest contributors to drilling fluid cost. From basic materials like DRILLING PAPER to proprietary blends like ENERLOC, we have solutions to bridge and seal from small thief zones to large fracture networks.
Loss Prevention and Treatment by Application
Preventing losses can be as simple as adding background material or as complex as a targeted blend to enhance the hoop stress of a weak zone (wellbore strengthening). AES Drilling Fluids provides a portfolio of material and engineering tools to address a wide range of scenarios. Technical expertise in conjunction with extensive experience results in low-cost, reliable solutions.
MULTIFIBER M lost circulation blend
LISTEN TO EPISODE 20 FOR MORE ON WELLBORE STRENGTHENING
LISTEN TO EPISODE 28 FOR MORE ON LOST CIRCULATION
Loss Categories
While definitions may vary, losses are typically broken into categories by the loss rate in barrels per hour. It’s important to recognize that while the loss rate is an important reference, the cause of the losses is essential to proper treatment. For example, a drilling induced fracture may be addressed through a reduced pump rate; however, a natural fracture requires treatment. Knowing potential loss zones and their properties helps to insure the correct materials are on location to pre-treat and respond to a lost circulation event.
Seepage Losses
Seepage losses are typically less than 10 bbl/hr. Seepage may be due to incomplete sealing of a permeable formation and the addition of background material of fibers and fine granules is usually effective.
Partial Losses
Partial losses range between 10 and 100 bbl/hr. Natural or partially induced fractures are likely causes. Medium to large granular materials help to treat partial losses.
Severe/Total Losses
Severe losses exceed 100 bbl/hr but can include complete loss of returns. Large fractures or gravel zones tend to be associated with severe losses. The loss of large whole mud volumes requires immediate action to insure the well remains filled. Treatment consists of squeezes, plugs, including cement if losses remain uncontrollable.
Wellbore Strengthening
Wellbore strengthening is the concept that appropriate materials can form a seal in a fracture to prevent further propagation. One theory of this mechanism is that loss prevention material enters the fracture mouth and forms a seal. The tip of the fractures is isolated and fluid leaks off, relieving the pressure in the fracture. Now the wellbore strengthening material is supporting the fracture mouth at the wellbore. Another theory is that the material enters the fracture, isolating the fracture tip with a solid plug.
Regardless of the mechanism, wellbore strengthening has the capability to increase a fracture gradient by a significant margin. Effective wellbore strengthening strategy requires proper engineering, materials, and execution. Modeling and laboratory testing is used to verify sealing potential. Products are available for a custom treatment and prepared materials are designed to seal common fracture widths.
Introducing MACRO STRENGTH
MACRO STRENGTH is an engineered, high fluid loss squeeze
(HFLS) material designed to solve lost circulation issues caused
by both natural and drilling-induced fractures.
In a recent case study, MACRO STRENGTH helped strengthen a weak shoe as the operator looked to improve their FIT by a large margin. A failed attempt to improve FIT using Tactical Blitz at 30 lb/bbl caused the operator to consider pumping a high fluid loss squeeze with MACRO STRENGTH as a last-ditch effort before calling cementers for a cement squeeze.
Introducing MICRO STRENGTH
MICRO STRENGTH is a new loss prevention and wellbore strengthening product designed by AES Drilling Fluids in our Houston R&D lab. The product is engineered to provide enhanced sealing and packing of fractures up to approximately 250 microns – a common size for most drilling-induced fractures and networks encountered. The material also features a significantly higher compressive strength relative to its peers, allowing for the material to withstand wellbore pressures and limit fracture propagation. As the material enters the fracture, it can seal and support the opening to strengthen the wellbore. The product can be used as background material or as part of a comprehensive lost circulation plan.
Loss Prevention and Treatment Case Histories
Featured Case History: ECM and ECM 2: Engineered LCM Package Stops Losses and Reduces Drilling Days in the Midland Basin
An operator drilling in the Midland Basin was facing significant losses at the start of a 4 well pad, requiring a reduction in circulation rates to limit equivalent circulating density (ECD). The lower pump rates minimized losses, but required lower drilling rates to account for reduced hole cleaning efficiency. Conventional treatments failed to provide a solution, so AES Drilling Fluids recommended utilizing a blend of ECM 1, ECM 2, and ENERLOC to cure the losses and return to normal drilling operations.
ECM 1 and ECM 2 are a complementary blend of loss prevention material designed to provide an optimized particle size distribution for treatment of lost circulation. For larger fractures, ECM 1 and ECM 2 work together with ENERLOC to cover an even larger particle size distribution.
The treatment consisted of 35 lb/bbl sweeps of 15 lb/bbl ECM 1, 15 lb/bbl ECM 2, and 5 lb/bbl ENERLOC each stand to mitigate losses. The losses were reduced and ultimately cured through the four well program. This enabled increased pump rates which saved a total of 2.5 days of drilling when compared to the initial well.
Select Loss Prevention and Treatment Additives from AES Drilling Fluids
Our suite of options are designed to address a broad set of lost circulation and wellbore strengthening scenarios. Contact your AES Drilling Fluids Account Manager to review product details for your application.
| Product | Description | Product Data Sheet | Associated Mud System(s) |
|---|---|---|---|
| CAL CARB MIX | Blend of acid soluble bridging/sealing material | CAL CARB MIX Product Bulletin | |
| CEASE & DESIST | Blend of granular and fibrous materials designed to seal a wide range of pore and fracture widths | CEASE & DESIST Product Bulletin">SILVERSEAL Product Bulletin | |
| CEDAR FIBER | Shredded cedar material | CEDAR FIBER Product Bulletin | |
| CHEMSEAL | Cellulose blend with fine and medium flake material | CHEMSEAL Product Bulletin | |
| CHEMSTOP O | Chemically treated bridging and sealing materials | CHEMSTOP O Product Bulletin | Oil-Based Muds Synthetic-Based Muds |
| DRILLING PAPER | Shredded paper material | DRILLING PAPER Product Bulletin | |
| ECM 1 | Fine and medium sized natural materials, fibers, and cellulose | ECM 1 Product Bulletin | |
| ECM 2 | Medium and coarse sized natural materials, fibers, and cellulose | ECM 2 Product Bulletin | |
| ENER-GS | A high performance resilient, angular, synthetic graphite for wellbore strengthening, lubrication and lost circulation | ENER-GS Product Bulletin | |
| ENERLOC | A proprietary, sized formulation designed to rapidly seal pores and fractures | ENERLOC Product Bulletin | |
| EOSEAL II | Proprietary blend of cellulose and polymer designed to provide wellbore stability by reducing fluid invasion into the microfractures | EOSEAL II Product Bulletin | |
| GXM | Medium-sized graphite blend for lubricity, filtration control, and to treat lost circulation | GXM Product Bulletin | |
| GXM PLUS | High performance crystalline graphite flake designed to enhance lubricity and filtration control | GXM PLUS Product Bulletin | |
| MACRO STRENGTH | High fluid loss squeeze material designed to solve lost circulation scenarios due to natural and drilling-induced fractures | MACRO STRENGTH Product Bulletin | |
| MICRO STRENGTH | A proprietary blend of materials designed prevent losses from drilling induced fractures | MICRO STRENGTH Product Bulletin | |
| MULTIFIBER F | A proprietary blend of fine fibrous lost circulation and pore bridging materials | MULTIFIBER F Product Bulletin | |
| MULTIFIBER M | A proprietary blend of medium fibrous lost circulation and pore bridging materials | MULTIFIBER M Product Bulletin | |
| PERMASEAL | A proprietary blend of graphitic and mineral fiber materials designed to provide rapid sealing | PERMASEAL Product Bulletin | |
| SILVERSEAL | A multi-component, proprietary sized blend of pore bridging and sealing agents developed to minimize fluid loss in permeable formations | SILVERSEAL Product Bulletin |