B FLUSHBY DOWNHOLE APPLICATIONS

1. Troubleshoot the well, for broken or stuck equipment and tools. 2. Production flushes.

3. Back-Flushing of Sand and Wax. Moreover coal fines in CBM/CSG wells

4. Fish broken sucker rods and polished rods. 5. Circulate fluid to kill the well.

6. Pull and run sucker rods.

7. For PCP, Flushbys can insert and change PC pumps or the rotor in tubing PCPs.

8. For RRP, Flushbys insert and change insert rod pumps. 9. Pressure test tubing and wellhead integrity.

10. Spacing and re-spacing rods. 11. Tubing rotations on RRP Wells.

C - FLUSHBY COMBINED APPLICATIONS (WITH OTHER EQUIPMENT)

1. Work with a continuous rod injector to run and service continuous rod.

3. Work with a coiled tubing unit to perform different stimulation and chemical treatments jobs

2. Flushbys work as ‘’Pressure Units’’ with different service equipment. 2. Service and change Polished rods.

Flowline

Fig. 3. The Various Applications of a Standard Flushby Unit

Advantages

Flushbys, as a result of the efficiency, flexibility and integration of equipment, are more effective than workover rigs for diagnosing wells that have stopped producing. Flushbys are a successful “first call” option to assist producers in determining the reason for well production issues. The limitations of flushbys are typically related to the fact that they are not configured to pull and run entire strings of tubing and they usually have a lower winch and derrick pull capacity; however, these limitations enable other, more beneficial, efficiencies.

Flushbys can be used in situations where a conventional workover rig would be too large or might not be readily available to perform a required intervention or surface work. Where flushbys can be used, they have proved to be more efficient than workover rigs, as they enable faster mobilization and rig-up and rig-down. An analogy to drilling operations illustrates this flushby advantage: Using a flushby is like using a large rig to drill a shallow well; a smaller-capacity rig could drill the well just as efficiently.

Flushbys can be set up more quickly and efficiently than a conventional workover rig. Experience shows that a flushby unit rig-up is up to 10 times faster than that of a workover rig. The flushby’s integrated systems and its free-standing mast, which does not require guy lines, are the main reasons for faster rig-up. It is interesting to note that most flushbys can set up in 15 minutes.

The major advantages of using flushbys have influenced many oil companies from North and South America to use these units as a “first call” option for well-problem diagnosis in their workover operations.

Typically flushbys are operated by two- to four-man crews (or an average of three), depending on job type. Crews are instructed to perform workover operations and are fully capable of safely performing specific functions. Reputable flushby operators focused on service quality and safe field operations will have in place comprehensive training systems, which ensure the crews can operate in a safe and environmentally sound, process-controlled manner.

An article published in the April 2005 edition of World Oil magazine, titled “What's New in Artificial Lift: Part 1—

Fifteen New Systems for Beam, Progressing-Cavity Pumping and Plunger Lift,”3 highlighted the benefits that flushbys and

…Significant savings can be realized in reduced servicing costs by using the pump in wells where change-out is frequent. In remote locations where a complete workover rig comes at a premium cost, the new pump allows servicing by less expensive means with a flush-by or other rod-pulling device. Weatherford recently used the new system in an application in Canada. The original pump in the horizontal oil well was pulled after 17 months in use. A flush-by unit performed the workover to replace the insert pump, using the new PCP, which took about 3 hours. An operation of this type with a standard PCP takes about 8 hours.…

Another article, published in the May 2009 edition of World Oil magazine and titled “What’s New in Artificial lift: Part 2

–More Development in Sucker Rods, Pumps, Gas Lift and Innovative Cable Pumps,”4 highlighted the applications and

advantages of using a flushby unit:

....Continuous Sucker Rod Systems. Weatherford International has two innovative technologies to service continuous sucker rods. The service system offered by Weatherford’s continuous sucker rod ‘Corod team’ is known as a Flushby. It is a compact truck mounted well servicing system equipped with a well servicing triplex pump, a large fluid carrying tank and a mast with drawworks, typically 50,000-60,000 lbs pulling capacity). The highly mobile service system is designed to quickly diagnose well problems, complete the service work and quickly get the well online. Tthe truck/system is fully equipped (including rod tongs and BOP) and virtually self-sufficient to perform many kinds of service work such as killing, circulating or flushing sanded wells; servicing sucker rods including pump changes, fishing parted tools; changing broken polished rods; repairing stuffing box packing; changing out PCP drives; and working with Weatherford’s Mobile Gripper to perform all continuous sucker rod service work. The gripper tool was designed specifically to work with any hoisting service equipment to pull or run in continuous sucker rod. It is an efficient method to get a well up and running and an industry first. The new tool was developed with input from major producers. The efficient prototype was built with virtually no major changes after field trials, and commercial operation began with deployments into North and South America and the introduction of new models capable of various pull capacities. Additional new models are in the design stage. The entire system can be rigged in or out in less than 30 minutes and runs continuous sucker rods in and out of the well at speeds exceeding 100 ft per minute. Weatherford also offers an innovative industry first, the Flushby Injector, which is similar to the Flushby but also has a permanent continuous sucker rod injector that can be used when required or stowed away when it is not. Hence, to summarize the main advantages of flushbys:

• Manufacturing costs are lower than for alternatives, while hourly rates for flushbys are lower as well (Fig. 4).

Fig. 4. Cost Savings Associated with Flushbys

Save $

Lower Operating Rate

Lower Manufacturing Cost Relative to Alternatives of same applications and

• Good maneuverability is one of the key features of flushbys, as they typically rig up in much less time than alternatives. Most flushby units can be rigged up in 15 minutes and rigged down at similar times or even less. In addition, as single, mobile, light trucks, flushbys travel faster to location (Fig. 5).

Fig. 5. Time Savings Associated with Flushbys

• Flushbys have all needed equipment mounted on one truck, including service tools. In addition, they carry fishing tools for all rod and pump breaks.

• They require fewer operating staff than alternatives do (Fig. 6).

Fig. 6. Comparison of Personnel Requirements between Flushby and Workover Rig

Case Study: Flushby Operating Time versus Workover Rig Time in an Oil Field in South America

A study was conducted on multiple oil wells of an average depth of 3,000 ft, located in a field in South America. The purpose was to compare the performance of a flushby relative to a service workover rig, for the same applications and in the same environment, from mobilization to rig-down time. Operations included

• insert beam change;

• polished rod change (beam); • polished rod change (PCP); • rod fishing.

Fig. 7 clearly shows the difference in performance between a flushby and a workover rig. Saving time here is the main

factor in saving cost; and at this rate, the flushby unit can perform two to three jobs daily (depending on the distances between well sites). By comparison, the workover rig can perform only one job daily.

Save Time

Faster travel times (Maneuverability)

Faster Rig up and Rig down times Relative to alternatives

11 5.5 6.5 16 18 16 17 23 0 5 10 15 20 25

INSERT BEAM PUMP CHANGE

POLISHED ROD CHANGE (BEAM)

POLISHED ROD CHANGE (PCP)

ROD FISHING Flushby Job Time / Hr. Workover Job Time / Hr.

Fig. 7. Time Comparisons of Jobs Performed with Flushby Workover Rig

Tables 1–4 and the accompanying Fig. 8–11 provide the breakdown of job times for both the flushby unit and the

Table 1. Time Requirements for Insert-beam Pump Change with Flushby and with Workover Rig