Qwater Well Developer - Model Production Series - Heavy-Duty Well Development Tools
While exhibiting at several large water well tradeshows, including the Florida Ground Water Association’s South Atlantic Well Drilling Jubilee, held in Myrtle Beach, and at the National Groundwater Convention and Tradeshow in Las Vegas, there were many requests for larger, heavy-duty well development tools; and plans for a Production Series began. These developers were designed primarily for small production wells in 4-inch and 6-inch diameters. After a year of design and well testing, the 4-inch and 6-inch Qwater Well Developers are now available.
The Production Series Qwater Well Developers are reusable. Both the 4-inch and 6-inch use the same tough ABS body and molded 1.5-inch steel female NPT pipe fitting for attaching to a weighted wireline or drill pipe. Although the casing/screen wipers are also made of tough polyurethane, there are four wipers on each ABS body to ensure that the tool only needs to go in the borehole one time. The wipers can easily be replaced in the field with a regular slotted screwdriver to remove the stainless steel bolt and slide the spacers on and off the ABS body to replace or change wiper sizes (4-inch or 6-inch).
This extra Spacer Ring may be used in place of removing two wipers (either 4-inch or 6-inch) to convert the well development tool into a less aggressive two-wiper well developer.
Attachment and Development Procedures
The new Production Series Qwater Well Developer surge block tools fit 4-inch and 6-inch Schedule 40 casing and screens. A check valve in the removable bottom of the tool allows for pumping sediments out of the well while surging. The 4-inch and 6-inch Qwater Well Developers can be used with a wireline (a cable attached to a 10-foot section of iron pipe) or drill rod.
Attachment of Tool – The top portions of the 4-inch and 6-inch surge blocks are fitted with a 1.5-inch female tapered NPT pipe thread for attaching a 1.5-inch male pipe thread. If a wireline is selected to lower the development tool into the well, it is recommended to attach a 10-foot long section of iron pipe directly to the top of the tool for weight to help lower the tool. Care should be taken not to over-tighten the threaded fitting. Hand tight plus one-half turn is sufficient. If the check valve assembly is to be used to pump water from the screen, a PVC riser should be attached to the top of the weight pipe and extended from total depth to land surface. A 90-degree elbow is recommended at the top to direct the purge water away from the wellhead. If the drill pipe is attached above the top of the tool, care should be taken to ensure that the weight of the drill rod does not crush the tool on the downstroke into the bottom of the well.
Development Procedures – Beginning at the bottom of the screen, using as short a stroke as possible (1-foot to 3-foot), begin slowly raising and lowering the tool. The polyurethane wipers fit very snugly and can damage even a metal screen if the upstroke is too fast. Screens are inherently weak and have great force pushing inward from the formation. Strong upstrokes can cause the screen to collapse due to the high suction (vacuum). Surging speed should not exceed 1/2 foot per second. Wells with slotted pipe screens generally take longer to develop than wells with wire-wrapped screens. If the check valve assembly is not used to remove the fines, the well development tool should occasionally be withdrawn from the well and the well screen pumped or bailed to remove fines in the bottom of the screen.
Continue to work the tool up and down, slowly, to surge the water back and forth, in and out of the well screen. The washing action will work the fines inward through the filter pack and screen, thus increasing the flow or permeability of the formation around the screen. Wells drilled with the drilling mud containing organic polymers may require an additive (such as Baroid’s Aqua-Clear) to break down the gel strength of the mud.
If the check ball and riser are used to remove the muddy development water, continue for 2 to 5 minutes per foot of screen to be developed, depending upon the amount of fines (clay, silt) in the formation.