Using a single universal spacer surfactant to clean a wide variety of oil-based mud (OBM) is considered the "Holy Grail" of spacer fluid system. Specialty chemical and service companies have devoted intense research and vast resources to develop the ideal spacer surfactant, but their efforts have not led to a singlesurfactant solution due to uniquely different drilling mud properties. It is no surprise to experts in the field that surfactant selection is extremely mud specific. For instance, one surfactant may effectively clean certain types of OBM, but fail in another mud from a different location that has the same density and base fluid. As a result, service companies have numerous surfactants in their portfolios, further complicating logistics and operations. This paper presents the discovery of a high-performance universal biomicromaterial, which can significantly improve the cleaning performance of any surfactants/spacer fluids to remove most, if not, all types of drilling mud. The innovative bio-micromaterial is an eco-friendly byproduct from another industry.
Successful cleaning of the drilling mud was demonstrated by standard rotor testing with different OBM samples from across North America, and the percentage of mud removal was determined. Furthermore, the ability of the innovative micromaterial to efficiently clean the mud was verified by measuring the strength of bonding between the set cement and the metal casing that had been cleaned by the spacer fluid after drilling mud contamination. Basically, this new procedure simulates downhole fluid displacement by the intermediate spacer fluid, which is ahead of the cement slurry, displacing the mud. Stability and mixability were also studied to determine the effect of the bio-micromaterial addition to the spacer fluid. Finally, a fundamental scientific study using thermogravimetric analysis and imaging techniques was done to characterize the material and determine its thermal stability.
For the first time, newly discovered, high-performance, universal cleaning micromaterial is presented to enhance the OBM removal of any spacer fluid design. This groundbreaking research has successfully demonstrated the unconventional advanced material to be a universal cleaning, single-additive spacer admixture for a wide variety of drilling mud from various regions across North America. To our knowledge, based on extensive literature search, this is the first report about the application of this natural waste product in wellbore cleaning fluids like the spacer.
This study will demonstrate a comparison of completion fluid designs in operations and production across several pads in Gonzales and Lavaca counties in the Eagle Ford Basin. The use of tunable friction reducers (FRs) significantly improves completion efficiency and production. The paper also illustrates how tunable FRs provide greater versatility at the wellhead by replacing multiple fracturing fluid systems such as conventional friction reducer and linear gel with a single additive.
When conventional FRs prove inadequate in slickwater designs, subsequent HVFR and linear gel designs are utilized. This study demonstrates that tunable FRs provide the flexibility to be run at lower concentrations as an effective and efficient friction reducer. Should the slickwater treatment be insufficient, the FR concentration can easily be increased to achieve improved results for pressure reduction and sand placement while minimizing chemical additives and equipment on location. In addition, this tunable FR is engineered with breakable linkages that minimize formation damage to help improving production.
Tunable FRs can be run at less concentration compared to conventional FRs while delivering the same friction reduction as slickwater. Increasing the concentration produces a higher viscosity similar to that seen in linear gel. This flexibility is achieved with less equipment and additives and can be executed on- the-fly while pumping. This design has enabled an operator in the Eagle Ford to complete more stages with less shutdowns and screenouts. Eliminating equipment and extra additives simiplified logistics, reduced the footprint and equipment-related non-produtive time (NPT). Overall, production results taken over the first 12 months show that wells completed with the tunable FR had noticeably superior performance in cumulative production, which is normalized by lateral length. These improvements can be attributed to the proppant transport capabilities and the breakability of the tunable FR, which minimizes residue left in the formation and, in turn, provides greater regain conductivity.
Additional benefits include simplified delivery and smaller jobsite footprint requirements, which lead to significant cost savings. The tunability of the FR allows it to be administered on the fly while pumping, giving design change flexibility, enhancing overall operational efficiency. Since there is no need of hydration unit or dry-on-the-fly (DOTF) unit used for hybrid linear gel design, fewer NPT hours due to equipment breakdown was seen on location.
Pernites, Roderick (BJ Services) | Brady, Jason (BJ Services) | Padilla, Felipe (BJ Services) | Clark, Jordan (BJ Services) | Ramos, Gladyss (BJ Services) | Callahan, Jaron (BJ Services) | Garzon, Ricardo (BJ Services) | Sama, Raymond (BJ Services) | Embrey, Mark (BJ Services) | Fu, Diankui (BJ Services) | Johnson, David (Independent Resources Management) | Richey, Nicolas (Independent Resources Management)
Increasing horizontals, narrowing annular gaps, more stringent cement regulations, fracturing with more stages and high pumping rates on top of more cost-efficient well completion are raising demand for lightweight cements, which are designed to prevent damage and lost circulation problems in weaker formations. However, many alternative lightweight materials that are more cost effective than glass beads, which are known to provide superior strength, are increasing waiting-on-cement time, thus delaying further drilling. They also struggle to deliver the required compressive strengths. This paper presents (1) recent case histories of successful field applications of new stronger non-beaded lightweight cement, (2) extensive laboratory data of various field designs with new lightweight cement versus premium commercial lightweight cements, and (3) detailed scientific study explaining how the innovative lightweight cement has provided superior fluid stability and set cement mechanical properties.
The successful field trials occurred in the Permian basin for all four wells on the same pad. About 400 bbl of the new lightweight cement at 10.5 lbm/gal density was delivered to complete each cementing job with 134°F BHST and 6,000-ft measured depth. The four wells were completed with the new lightweight cement, remarkably having no glass beads despite the extremely low density. Unlike the previous job designed with commercial lightweight cement, the new cement has provided far greater compressive strength and has shown faster (18 to 24 hr) strength development. During placement, the new lightweight cement slurry has demonstrated exceptional stability with fewer additives than the previous design, thus simplifying field operations. Multiple laboratory test data at different cement densities (10.5 to 14.5 lbm/gal) for other regions confirmed the enhanced performance of the new lightweight cement in both slurry form and set cement over conventional lightweight technologies. Detailed scientific study via X- ray Diffraction (XRD) explained how the new lightweight cement provided superior set cement performance.
The novelty of this work and invaluable contribution to the industry is the first successful field application of a newly developed micromaterial that provided a lighter, stronger, low-permeability, non-beaded cement that enhances wellbore integrity and provides better zonal isolation. New findings from XRD and Scanning Electron Microscopy (SEM) imaging techniques about the new micromaterial lightweight additive may provide insights for improving the performance of traditional materials.
Rollins, Brandon (Whiting Petroleum Corporation) | Lauer, Travis (Whiting Petroleum Corporation) | Jordan, Andrew (BJ Services) | Albrighton, Lucas (BJ Services) | Spirek, Matthew (BJ Services) | Pernites, Roderick (BJ Services)
Frequently exposed weak formations require the use of lighter slurries, and with increased wellbore pressures encountered during fracture stimulations, stronger cements are essential. Lighter, stronger cementing technologies are the key to ensuring well integrity and enabling simple, cost-effective well construction designs.
This paper describes the benefits and features of newly developed, lightweight cementing materials available for operations in the Williston Basin. Applications of these materials are supported by case histories and extensive laboratory test data.
Regionally, materials have been identified that can be used to produce innovative, bulk lightweight cementing systems. These materials can be inter-ground with the cement during manufacturing or blended with bulk cement. Both methods create cost-effective, high-strength cement systems that can easily be formulated into slurries with densities as low as 10.5 ppg.
Comprehensive laboratory test data was generated to support well simulations and field trials of the new materials. Field trial data is then analyzed to illustrate the benefits of cement systems.
Economical lightweight cements are commonly produced with fly ash extended systems, however, these systems have low strength at low densities. Lightweight, high-strength, fit-for-purpose cement materials are common in southern oil and gas basins, but transporting these materials to northern states is cost prohibitive. Exotic solutions to create lightweight cements (nitrogen foams or hollow glass micro-beads) are available but expensive, adding considerable operational complexity.
Laboratory data demonstrates mechanical properties of the cement systems, slurry properties and set characteristics. The new, low-density cement systems show far greater compressive strengths than conventional blends. Conventional slurry provides a compressive strength of 500 psi, whereas the new low-density 12 ppg blends provide compressive strengths greater than 1,000 psi.
Additional practical benefits of these systems are illustrated by varying water content to improve slurry density from 11 to 13.5 ppg without additional cementing additives.
Multiple case histories illustrate the results of the applications of these materials at downhole temperatures ranging from 140°F to 220°F and well depths up to 11,000 ft TVD in the Dakota, Mowry and Charles Salt formations.
The limitations associated with traditional cementing materials will no longer restrict the creation of efficient well designs in northern states with the implementation of new, low-density cement systems necessary to exploit these oil and gas basins. Using lighter, stronger cement technologies will provide simple, cost-effective designs that are needed to ensure wellbore integrity in the Williston Basin.
The high intensity of hydraulic fracturing in unconventional reservoir has resulted in dramatic increase in water consumption. The reuse of produced water has been driven by both the environmental and economic benefits. The performance of conventional anionic friction reducers is usually affected by the total dissolved solid (TDS) in the water source. We present here a cationic friction reducer which is fully compatible with most of produced water based on results from the lab and field.
A cationic friction reducer was studied in the lab in synthetic brines and produced water from different Basins with TDS up to 275K. Friction reduction was measured at various concentrations of monovalent, divalent and trivalent cations in the brine. The impact of SO42- was also studied as a representative anion. Several field produced water with different level of TDS were also tested to prove the full compatibility. The additional benefit of using this cationic friction reducer is to control the clay swelling demonstrated by CST result. In the field, the cationic friction reducer was successfully applied in the slickwater jobs in North America using 100% produced water, resulting in high pumping rate with low wellhead pressure.
The cationic friction reducer shows excellent friction reduction even in very high TDS. It also exhibits good tolerance to all the cations and anions, most of which usually are problematic for anionic friction reducers. For the jobs performed, the treating pressures were well below the limit at designed pumping rates, and all proppants were placed as planned. The cost saving was significant by using produced water instead of fresh water. The results from the lab and field demonstrate that this cationic friction reducer is a good candidate for wells to be completed with 100% or diluted produced water.
This paper presents a solution to the wells that require or prefer to use produced water in their slickwater jobs. The field data shows that it saves horsepower during operation due to the high friction reduction in produced waters. It also lowers the cost related to produced water disposal and fresh water transportation.
Pernites, Roderick (BJ Services) | Brady, Jason (BJ Services) | Padilla, Felipe (BJ Services) | Clark, Jordan (BJ Services) | McNeilly, Caitlin (BJ Services) | Iqbal, Waqas (BJ Services) | Lacorte, Juan (BJ Services) | Gonzalez, Eduardo (BJ Services) | Embrey, Mark (BJ Services)
Delivering a competent cement seal to provide wellbore zonal isolation for maximizing production is highly dependent on mud removal, which remains the perennial challenge. Non-aqueous mud is preferred during drilling to avoid formation swelling and for HTHP wells, but it is highly incompatible with aqueous-based cement fluid. More challenging, non-aqueous mud is customarily recycled and reused in multiple wells, contaminating it heavily and making it difficult to clean by many conventional spacers.
This paper presents a full-scale laboratory development to a successful field application of an unconventional spacer with a novel micromaterial that enhances mud removal and provides exceptional fluid stability (flat viscosity), important for long horizontals. Due to its differentiating chemistry combined with uniquely engineered physical properties (minimally abrasive yet non-damaging to equipment), the new micromaterial allows more efficient scouring of strongly adhered mud from casing/formation surfaces, which many traditional spacers have difficulty removing efficiently.
To demonstrate efficient mud removal, numerous standard rotor cleaning tests were performed with different muds from across North America. Free water and HPHT dynamic settling tests were used to evaluate thermal stability of the spacer. Wettability and API compatibility tests were completed. XRD and SEM analyses were used to characterize and understand the unique properties of the novel micromaterials that contribute to enhanced mud cleaning. First field application was successfully completed in the Permian Basin. Field trial has proven the new spacer (11.3 ppg design with 134 bbl total volume) to be highly stable when pumping down (5 bbl/min) into a wellbore of over 20,000 ft (6096 m) depth with ~12,000 ft (~3658 m) horizontal and 139°F (59°C) BHCT. Most of the oil-based mud used during drilling was recovered.
The Bakken was one of the first US shale basins in which fracturing techniques were applied to recover oil. The crude oil production in the Bakken surpassed the record set in December 2014, reaching a new high of 1.273 million bbl/day in early 2018. The treatment design has always been an essential part to maximize oil recovery from the reservoirs. There have been some papers reporting individual well studies and data analysis purely based on public databases, but very few provided a direct comparison of different treatments on several well pads in close proximity.
This paper studied the two popular fracture fluid systems, slickwater and hybrid treatment, at adjacent wells in the same area with the same operator and service provider in the Bakken. This method provides the most statistically reliable comparison by minimizing the possible contributions from all the other factors, like well reservoir property, completion design and operation execution. There were 10 slickwater jobs and 9 hybrid jobs on several pads within a 3-mile radius. Both treatment methods were applied on each pad during zipper fracturing. The hybrid jobs used friction reducers during the pad and moved on to crosslinked guar fluid when sand was pumped. For slickwater jobs, friction reducers were used through the entire treatment. Fracturing fluid usage, proppant intensity and pumping rate were compared, as well as the well production at 3, 6 and 12 months.
The production data showed that even with 28% less proppant pumped during the job, the wells treated with slickwater had significantly higher long-term production. In addition, by replacing the hybrid jobs, the chemical and equipment requirements onsite were also largely reduced. These direct comparison results can help future fracturing job designs to improve oil production in terms of fluid system, proppant intensity and pumping rate.
Tower, Patrick (BJ Services) | Williams, Austin (BJ Services) | Sakievich, Sam (BJ Services) | Howdeshell, Tony (BJ Services) | Kearley, Patrick (BJ Services) | Motruk, Lonny (BJ Services) | McCullough, Tony (BJ Services)
High Reliability Organizations (HROs) are organizations with systems that maintain exceptionally low failure rates while operating in environments where the nature of the risk and complexity of serious incidents would be anticipated. HROs such as nuclear submarines, aircraft carriers, and the fire service have no fail missions because the costs of failure are extremely high. Applying the same systems and tools that created their passionate commitment to excellence that permeates every aspect of their operations, other industries can produce their own culture of high reliability where nearly perfect safety and service quality are the norm.
The aim of this paper is to illustrate how the principles, concepts, and processes of HROs, including Crew Resource Management (CRM), can optimize operational execution of a pressure pumping company through increased levels of safety and quality. The contemporary oilfield operating environment requires teams to be proactively aware of emerging threats and to trap errors or incidents to prevent them from escalating into significant incidents.
The paper includes the following themes: A literature review of the principles and concepts of traditional and established HROs from other industries; The process and systems to operationalize HRO principles and concepts within the energy industry; and Two case studies demonstrating how HRO principles and concepts allow teams in the oilfield to reduce system failures and to notice, confront, resolve, and learn from unforeseen problems and failures when they do occur.
A literature review of the principles and concepts of traditional and established HROs from other industries;
The process and systems to operationalize HRO principles and concepts within the energy industry; and
Two case studies demonstrating how HRO principles and concepts allow teams in the oilfield to reduce system failures and to notice, confront, resolve, and learn from unforeseen problems and failures when they do occur.
Tower, Patrick (BJ Services) | Williams, Austin (BJ Services) | Sakievich, Sam (BJ Services) | Howdeshell, Tony (BJ Services) | Kearley, Patrick (BJ Services) | Motruk, Lonny (BJ Services) | McCullough, Tony (BJ Services)
High Reliability Organizations (HROs) are organizations with systems that maintain exceptionally low failure rates while operating in environments where the nature of the risk and complexity of serious incidents would be anticipated. HROs such as nuclear submarines, aircraft carriers, and the fire service have no fail missions because the costs of failure are extremely high. Applying the same systems and tools that created their passionate commitment to excellence that permeates every aspect of their operations, other industries can produce their own culture of high reliability where nearly perfect safety and service quality are the norm. The aim of this paper is to illustrate how the principles, concepts, and processes of HROs, including Crew Resource Management (CRM), can optimize operational execution of a pressure pumping company through increased levels of safety and quality. The contemporary oilfield operating environment requires teams to be proactively aware of emerging threats and to trap errors or incidents to prevent them from escalating into significant incidents.
Wellbore cementing is critical for zonal isolation, bonding and supporting the casing downhole. In this paper, a novel high-performance micromaterial is presented for significantly improving the quality of the cement slurry and set cement tested in different API cements for horizontal wells. Its performance is compared to conventional Pozzolanic materials currently used in increasing cement properties. Strongly attractive for cementing horizonal wells, the innovative micromaterial provides excellent slurry stability, free water control, particulate suspension, and additional fluid loss control to superior set cement properties including high early compressive and tensile strengths, extremely low permeability, and zero shrinkage. This material offers consistently high performance and no variability of product quality as compared to Pozzolan materials that are derived as a by-product of coal burning.
The key novelty and invaluable contribution of this research to the field is the application of a unique high-performance micromaterial that can deliver multiple desirable properties in both slurry and hardened cement. With the illustration of the material giving many good surprising properties, the cement design can be optimized by reducing the dosage of several cement additives in the admixture, giving potential cost savings to service companies or operators. During our investigation, the new material does not require an additional chemical to activate its unique functionality.