BMP of Oil and Gas Development

BMP Spotlight: Scott Environmental Services INC.

SESIRecognizing the enormous problem of waste generated by the oil and gas industry and the need for reducing the environmental footprint of operations, Scott Environmental Services Inc. (SESI) is a progressive company providing environmental waste management services to the oil and gas industry.  SESI brings innovative solutions to the variety of environmental, safety and operational problems of the industry approaching each problem with an understanding of the latest technologies, in a cost-effective manner, and in accordance with best management practices.   In their work, SESI applies the Environmental Protection Agency’s (EPA) waste hierarchy of methods  – source reduction, recycling/reuse, treatment, and disposal. 


Reliable Results Through Proven Approaches

SESI’s services focus on source reduction, seeking cost-effective ways of minimizing waste.  The company specializes in the recycling/reuse of oil and gas well drill cuttings and heavy mud, such as the construction of new roads or drill pads, through their signature Firmus® process (see below).  Their DuroSM, pHixitSM, and DBurialSM services address treatment options, and DuroSMLandspreading, DBurialSM and TBurySMservices address waste disposal. These services are provided as either design/build projects, which reuse or recycle the excess solid waste, or design/close projects, which provide treatment and/or disposal options.

All of the SESI services, including complete waste planning projects, utilize sampling and testing to:

    1. identify constituents of the waste; 
    2. determine the most appropriate and cost-effective reuse, treatment and/or disposal options; and
    3. verify success or indicate additional treatment requirements.

Solid Drilling Waste

“Solid waste” from an oil and gas operations can include solid, semi-solid, liquid, or contained gaseous material.
40 C.F.R. 257.2 Definitions

SESI specializes in solid drilling waste that is a mixture of mud and cuttings that cannot be pumped from the site. This mud often contains solids, liquids and other materials that would contaminate the local environment if not handled properly.

Since oil and gas exploration and production waste is not generally a hazardous waste under RCRA, individual states regulate disposal for these wastes. Practices can vary widely from state to state, although RCRA intends that states take adequate measures to ensure that solid waste is disposed of without affecting human health or the environment.  This includes taking into account the hydrogeologic systems that may allow for the migration of contaminants.

Contaminants

“[M]aterials used and wastes generated in exploration and production operations should be managed by considering risk to human health and the environment via media pathways”
[API E5].

Contaminants are found in drilling mud waste and can usually be broken down into four broad categories:

Salts – electrical conductivity, sodium absorption ratios, exchangeable sodium percentages, and chlorides.
Hydrocarbons – total petroleum hydrocarbons, oil and grease, and benzene.
Metals – arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver.
pH, which impacts the other components solubility in water.

Each must be analyzed with tests typical to their category. The concentration of each of these contaminants is important in determining how the waste will affect the environment and as a result it is critical that they are tested for and managed accordingly.

Contaminants may be transported by three different naturally occurring media – water (both groundwater and surface water), soil, and air.   The proper management of these wastes is important when protecting the environment as well as human health. All three of these media allow for the transportation of contaminant materials from their original sources to the natural environments surrounding them.

SESI’s Design/Build Services

SESI’s Design/Build services are considered reuse/recycle options under the waste hierarchy.  These services include the engineering for closure, the work to reuse and recycle the waste, and the confirmatory testing of the recycled material.

Firmus® Process

This proprietary service was developed by SESI over several years for use on fresh-water mud and cuttings, oil-based cuttings, and some saltwater mud and cuttings.  The service treats drilling waste with solidification and stabilization technology so that it can be reused as construction material for lease roads, drilling pads, compressor station pads, tank battery berms, and other load-bearing structures.  The service is typically broken down into two phases:

Firmus® Plasticity Reduction (Firmus® PR), and
Firmus® Construction.

Firmus® PR is designed to reduce the plasticity, dry, and prepare the mud and cuttings for reuse.  The resulting material is then transported to the location of the structure to be constructed.  At this point, the Firmus® Construction phase is performed.  This phase includes further stabilization and shaping of the material to meet the desired loads that will be placed on it.  Also during this phase, final samples are taken for confirmation of meeting the closure criteria.

The benefits of the Firmus® service is that it takes waste that is otherwise disposed onsite or offsite and reuses the material for the creation of structures that would otherwise need new raw materials to build.  Firmus® services also reduce the customers’ environmental footprint, and mitigate the customers’ future liability.

From past experience, we have learned that the Firmus® service is most effective when a customer has high contaminant levels, transports the waste offsite for disposal, and/or has multiple wells to drill in a given area.

SESI Firmus Process
This roadway portion was built by SESI using its Firmus® process from water-base mud and cuttings from a reserve pit. See the full report at Pecos Experimental Roads Project.

DuroSM Process

This proprietary service was developed by SESI over several years for use on fresh-water mud and cuttings, oil-based cuttings, and some saltwater mud and cuttings, too.  The service treats drilling waste with solidification and stabilization technology so that it can be reused as a load-bearing structure for setting frac tanks or other equipment during completion or after completion.  This is typically accomplished by solidifying and stabilizing the mud and cuttings within the confines of the pit area.

The DuroSM service is similar to Firmus® in that it prepares the mud and cuttings for use and then further stabilizes them to support loads.  The DuroSM process also immobilizes the contaminants to reduce their mobility in the environment.  By reusing the waste to support loads over the pit area, the customer’s environmental footprint is reduced, the use of other construction materials is reduced, and the potential for future liability from the waste is reduced.

The DuroSM process is most effective when the customer’s waste has high contaminant levels and/or is being transported offsite for disposal.

SESI’s Design/Close Services

SESI’s Design/Close services are considered treatment and/or disposal options under the waste hierarchy.  These services include the engineering for closure, the work to treat and/or dispose of the waste, and the confirmatory testing of the waste.

TBurySM Process

This service is basic trenching and burying of solid drilling waste.  It is only used when there are no contaminants with concentrations above the closure criteria except for pH.  If there is a pH issue, then our pHixitSM service is utilized in conjunction with TBurySM.  This is considered a disposal option.

DBurialSM Process

This service is used when the solid drilling waste has low-level contaminants and can be disposed onsite by burial.  The service utilizes existing soil around the pit area to dilute the solid drilling waste contaminants below the closure criteria.  This service can also be utilized in conjunction with our pHixitSM service.  This is considered a treatment and disposal option.

Landspreading

Landspreading is similar to DBurialSM in that it is used when there are low-level contaminants and uses dilution to address contaminant issues, but the solid waste is spread over the land instead of being buried.  Once the solid waste is mixed with the soil it should be below the closure criteria.  This service can also be utilized in conjunction with our pHixitSM service.  This is considered a treatment and disposal option.

pHixitSM Process

We use this service when the pH is above or below the closure criteria.  pHixitSM is designed to adjust the pH of the solid drilling waste.  The service is almost always used with another Design/Close service.  This is considered a treatment option.

DuroSM Process

When there is no load-bearing structure use for the pit area, DuroSM is considered a treatment and disposal option.  This service is further detailed under Design/Build.

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