Removing proppants from the well flow
Proppants play a crucial role in hydraulic fracturing in oil and gas production. These small, durable particles are mixed with water and chemicals and injected into reservoirs. Their job is to seep into the tiniest fractures and cracks opened by high pressure hydraulic operations. Like miners prop up their mineshafts with timber to avoid collapse, drillers prop up these fissures with proppants, allowing them to stay open and facilitate the efficient extraction of hydrocarbons.
Proppants come in various forms, such as sand, ceramic beads, and resin-coated particles, each with unique properties to suit different geological and operational conditions. Proppants are typically in the 100-to-2 000-micron size range, carefully selected according to the characteristics of the formation. Crush resistance, chemical stability, adhesion quality, and abrasion resistance are important factors. While proppants have significantly contributed to the economic viability of resource extraction, their use is not without environmental risks.
The proppants are hydraulically pumped into cracks and fissures are designed to stay stuck, either due to their shape and size or because of the sticky resin coating them. However, the sheer volume of proppants used – several thousand tons in some operations – may cause a significant surplus to migrate into the well flow, ending up downstream for collection by facility separators. Sooner or later, any proppants that have migrated into the wellflow and collected in the facility separator will need to be removed, either manually or by using specialized cleaning methods like jetting.
Jetting operations are used to clean out separators that have accumulated sand or proppants. This process involves slurrifying the sand or proppant with water, creating a mixture that can be more easily removed from the separator tanks. Solids that are produced to surface (including proppants and reservoir sand) typically also carry oil-residue to surface.
On the Norwegian Continental Shelf (NCS), jetting operations are calculated to comprise about 44 tons (on average), or 58 cubic metres of oil emitted to the sea on average per year. Jetting operations typically empty separator tanks for accumulated sand. But jetting proppants to the sea is typically not allowed on the NCS without a dispensation granted by the environmental authorities. More often than not on the NCS, dispensations are granted. This is a point of environmental concern, especially when there is an efficient and cost-beneficial way to collect the proppants and avoid direct discharge into the sea by jetting.
Proppants come in various forms, such as sand, ceramic beads, and resin-coated particles, each with unique properties to suit different geological and operational conditions. Proppants are typically in the 100-to-2 000-micron size range, carefully selected according to the characteristics of the formation. Crush resistance, chemical stability, adhesion quality, and abrasion resistance are important factors. While proppants have significantly contributed to the economic viability of resource extraction, their use is not without environmental risks.
The proppants are hydraulically pumped into cracks and fissures are designed to stay stuck, either due to their shape and size or because of the sticky resin coating them. However, the sheer volume of proppants used – several thousand tons in some operations – may cause a significant surplus to migrate into the well flow, ending up downstream for collection by facility separators. Sooner or later, any proppants that have migrated into the wellflow and collected in the facility separator will need to be removed, either manually or by using specialized cleaning methods like jetting.
Jetting operations are used to clean out separators that have accumulated sand or proppants. This process involves slurrifying the sand or proppant with water, creating a mixture that can be more easily removed from the separator tanks. Solids that are produced to surface (including proppants and reservoir sand) typically also carry oil-residue to surface.
On the Norwegian Continental Shelf (NCS), jetting operations are calculated to comprise about 44 tons (on average), or 58 cubic metres of oil emitted to the sea on average per year. Jetting operations typically empty separator tanks for accumulated sand. But jetting proppants to the sea is typically not allowed on the NCS without a dispensation granted by the environmental authorities. More often than not on the NCS, dispensations are granted. This is a point of environmental concern, especially when there is an efficient and cost-beneficial way to collect the proppants and avoid direct discharge into the sea by jetting.
Removing proppants with FourPhase
Internationally, many operators install dedicated cyclonic separators to remove proppants during cleanout operations, and then switch to regular separators for flowback. FourPhase products, however, offer the ability to separate both proppants and sand during all production phases, ensuring optimal production flow during the entire well lifetime. Proppants come in a size range that is ideal for separation by a DualFlow desander. The desander stops 99.8% of sand and proppants upstream of the production separator in the 20 – 10 000-micron range (DNV certified).
A 5K psi DualFlow de-sander has the capacity to handle both initial cleanout with large amounts of proppants as well as regular flowback with a mix of proppants and sand. No mechanical switchouts are required, along with the inevitable production stoppages. Instead, you have continuous production. Optimized for maximum production flow and solids removal, bringing a range of benefits from the purely financial to the environmental.
From our viewpoint at FourPhase, the current situation with widespread dispensations for jetting proppants to sea is not sustainable. Dispensations do not remove the potential environmental impact that discharges to sea will have. Only separating the proppants from the well flow and treating them as the potentially harmful waste that they are, will reduce the environmental impact.
We believe that operators can have the best of both worlds. Separating the proppants upstream – before the production separators - removes jetting emissions from separators, saves erosion issues downstream and enables optimal production flow during all well phases. Optimized production flow just works. The separated proppants and other solids enter the established waste handling processes on any production facility and are handled according to environmental regulations. Oil and gas move on to the production separator and does not require further treatment.
A 5K psi DualFlow de-sander has the capacity to handle both initial cleanout with large amounts of proppants as well as regular flowback with a mix of proppants and sand. No mechanical switchouts are required, along with the inevitable production stoppages. Instead, you have continuous production. Optimized for maximum production flow and solids removal, bringing a range of benefits from the purely financial to the environmental.
From our viewpoint at FourPhase, the current situation with widespread dispensations for jetting proppants to sea is not sustainable. Dispensations do not remove the potential environmental impact that discharges to sea will have. Only separating the proppants from the well flow and treating them as the potentially harmful waste that they are, will reduce the environmental impact.
We believe that operators can have the best of both worlds. Separating the proppants upstream – before the production separators - removes jetting emissions from separators, saves erosion issues downstream and enables optimal production flow during all well phases. Optimized production flow just works. The separated proppants and other solids enter the established waste handling processes on any production facility and are handled according to environmental regulations. Oil and gas move on to the production separator and does not require further treatment.
Proppants, as harmful as microplastics
Both the proppants themselves and the chemical fluids used pose environmental risks. The resin-coated proppants are treated with phenolic, epoxy, furan, polyester, or polyutherane resins. On the NCS, the resin-coated proppants are categorized in the Red environmental impact group; the second most harmful category as defined by the Norwegian Environment Agency. The coatings are of similar chemical composition as paint, with low degradability and potentially harmful effects on par with microplastics.
Microplastics are a significant environmental concern due to their widespread presence and potential impact on ecosystems. The plastic particles less than 5 mm in size may contaminate water bodies, be mistaken for food by marine life, accumulate in animal tissues, terrestrial ecosystems and potentially enter the human food chain. The health implications of ingesting microplastics are still not fully understood, but research suggests that these particles may also have the potential to carry harmful chemicals and additives that could pose health risks.
Case studies of successful FourPhase projects show that our technology has proven capable of removing this environmentally harmful waste before it is jetted to the marine environment. There should be no reason for applying for or granting dispensations for jetting proppants or oil contaminated solids when our equipment is readily available. FourPhase desanders provide a range of benefits that will improve all production aspects and deliver production flow optimized for both environmental and financial purposes. All FourPhase equipment is available as a service, providing a low entry and Capex cost.
Link to Coiled Tubing operational info and case studies
Microplastics are a significant environmental concern due to their widespread presence and potential impact on ecosystems. The plastic particles less than 5 mm in size may contaminate water bodies, be mistaken for food by marine life, accumulate in animal tissues, terrestrial ecosystems and potentially enter the human food chain. The health implications of ingesting microplastics are still not fully understood, but research suggests that these particles may also have the potential to carry harmful chemicals and additives that could pose health risks.
Case studies of successful FourPhase projects show that our technology has proven capable of removing this environmentally harmful waste before it is jetted to the marine environment. There should be no reason for applying for or granting dispensations for jetting proppants or oil contaminated solids when our equipment is readily available. FourPhase desanders provide a range of benefits that will improve all production aspects and deliver production flow optimized for both environmental and financial purposes. All FourPhase equipment is available as a service, providing a low entry and Capex cost.
Link to Coiled Tubing operational info and case studies