【系列专题】页岩油的创新时代：生产回忆录（3）

DIVERTER SYSTEM ALLOWS OPERATORS TO MAINTAIN MORE CONSISTENT STIMULATION VOLUME

T’ S diverter system is the most economical and adaptable diverter on the market, according to the company. S Perf PODs are an interwellbore diverter designed to seal both circular and irregular-shaped holes, providing a solution for new completions and refracturing operations. S Perf PODs seal inside the perforation, eliminating any formation damage or residual fracture obstructions. S diverting technology allows operators to reduce the number of bridge plugs within a wellbore while maintaining the advantages of closer stage spacing and additional clusters. The risk of a preset plug can be drastically reduced along with pump down time, completion cost and resources associated with the corresponding wireline runs and subsequent mill out work. Applying  between bridge plugs allows the operator to achieve maximum cluster efficiency while stimulating the entire stage without leaving orphan clusters behind. S Perf PODs are available in both degradable and millable materials optimized for each wellbore based on bottomhole temperature and pressure ratings. Deployed from surface, Perf PODs are launched during the fracture to divert flow, allowing subsequent breakdown and perforation isolation.

COMPOSITE FRACTURE PLUG IMPROVES PNP SPEED, RELIABILITY

Plug-and-perf(PNP) completions favored among unconventional operators are process-intensive. Composite plug drillouts can take days, and the plugs can become stuck in the wellbore or set prematurely, resulting in unplanned interventions. T composite fracture plugs deliver a new level of efficiency and reliability in PNP operations using a streamlined design that is also more robust than competitive offerings. The plug, which features a single set of slips vs. the conventional two sets, contains 40% less material and is shorter in length compared to standard plug designs. The plug cuts millout times by an average of 50% without sacrificing strength or reliability. The plug also incorporates an ultradurable slip ring and contains no ceramic or carbide buttons to reduce the risk of sticking and plug presets. An Oklahoma operator recently ran 33 T composite plugs in a 4,572-m (15,000-ft) well with a 3,048-m (10,000-ft) lateral section at an average rate of 122 m/min (400 ft/min)—almost double the average run-in speed for standard plugs in previous jobs. No sticking or presets resulted in zero plug-related nonproductive time during well completion. Drill-out time was cut by 80%, from 15 to 3 minutes per plug, and all plugs were drilled out in a single trip using a V drillbit. The smaller overall volume of cuttings enabled easier, more effective wellbore cleanup.

NEW REAMER SHOE HELPS RUN CASING TO TOTAL DEPTH

D has released R, an aggressive reamer shoe with an integrated polycrystalline diamond composite (PDC) cutting structure. Building off the Pen-O-Trator design, R features a wellbore-seeking eccentric guide nose to negotiate troublesome formations, anti-aggressive left-hand blades to minimize torque, a PDC millable nose for drillout and a casing-friendly tungsten carbide cutting structure on the body. R has been designed specifically for use in applications where hole wall quality is a concern for getting casing run to total depth. Shale formations pose several challenges for effective casing running because they are prone to swelling, sloughing, ledging and formation shifts—all of which leave casing stuck or wear out traditional casing shoes. To combat these problems, D has enhanced the alloy compound of the nose, providing improved wear and erosion resistance. The R also features three rows of PDC cutters along the nose for a true cutting structure to remove formation as needed while casing is run to bottom.

EXPANDABLE LINERS LEAD TO PRECISE REFRACTURING APPLICATIONS

Operators are taking advantage of improved fracturing designs to increase production and EURs of mature and largely impermeable shale wells. Various mechanical and chemical refracturing techniques have been employed with mixed results. For example, sealing off older unproductive perforations with particulates is unpredictable, unreliable and requires multiple attempts. Even then, sustained integrity remains a question. Chemical diverting agents lack internal pressure integrity and tend to follow the path of least resistance. These limitations led E to develop the expandable refracturing liner. The liner provides a new wellbore with zonal isolation of existing perforations and internal pressure integrity that enables greater predictability of planned fracture stages. This method translates into a faster payback on investment and extended production life. The E Liner increased flow area by 47% compared to the conventional recompletion option. Ten expandable seals placed along the liner ensured accurate isolation of old perforations, enabling the operator to effectively apply lessons learned for an optimal refracturing program with a new wellbore. Surface pressures during the refracture were identical to those during the initial fracture, indicating that the E Liner enabled the operator to fracture into a new, untouched reservoir.

TOOL’S USES INCLUDE REAMING, TUBULAR DEPLOYMENT AND CASE SCRAPING

G’s H family of tools provides a variety of functions in the life of a well. This system can be configured and run as a high-speed reaming solution for casing or tubular deployment or used as a casing scraper with integrated wire brush. The system also can be used as a jetting tool for wellbore cleanup operations. With rotary speeds in excess of 1,500 rpm, the H is an ideal candidate for casing and liner cementing operations since the fluid pattern created at the shoe ensures better mud condition is achieved and should minimize cement/mud contamination during cementing. The H is designed to replace standard cementing and guide shoes by combining their respective features, extending their possible application. When the pumps are on, the circulated fluid is channeled through the central spline of the H tool and then forced through grooves in the inner sleeve via a set of impellers. This process results in high rotational speeds, low pressure drop and low torque, making this a natural fit for high-angle horizontal well cementing operations. The H has a low-torque high-speed casing/ cementing/reamer shoe that provides sufficient torque to get through slight obstructions in the borehole such as cuttings beds, debris and slight tight hole conditions. The tool also has a multijet nozzle configuration with a center jet that ensures radial deposition of fluids as well as a limited downward jet, which reduces contamination between fluids when displacing cementing. The center jets can be blanked off to concentrate fluid direction toward the borehole walls. This is relevant for cuttings beds agitation and shale breakouts.