FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

C4 ; `S#, f C. During the development of the well, a stream of clear water shall be introduced into the top of the graveling pipe to help wash that section of the gravel pack located above the perforations or standing water level. The I volume of water added shall be sufficient to give a washing action (at least 10 gallons per minute) to remove the mud and silt from the gravels. D. Timing: Air lift swab development of each well shall proceed for a minimum of 60 hours. Development by surging and pumping shall proceed for a minimum of 48 hours for each well. Proposed duration shall be approved by the Engineer, but actual duration shall continue until no further removal of sand and drilling material is observed. Development shall begin at the top screen section and the work will proceed downward. The Contractor shall bail the well when required to remove any sand and debris drawn into the casing by the development procedure. The Engineer shall be notified in �o advance so that he may witness the development. l E. Development with Air-Lift Swabs: 1. The Contractor shall commence development with an air-lift swab S between 24 and 48 hours after completion of the annular seal. Swabbing of the well shall be done with a close-fitting single and double swab whose outside diameter of the surge blocks shall not be more than �.. 118-inch smaller than the inside diameter of the screen section. The surge blocks for the double swab shall be separated by 10 to 20 feet by a perforated piece of drill pipe. Sufficient perforations shall be drilled (,(� between the surge blocks for passage of at least 200 gpm. 2. Within 12 to 24 hours prior to commencement of development, the Contractor shall inject a concentrated solution of dispersing agent into the screened sections in a manner acceptable to the City. The dispersing agent shall be premixed with water before introduction into the well. After the solution has been added, clean water shall be added to the well to force the solution through the screen into the formation. -a. The dispersing agent shall be a solution of sodium acid pyrophosphate (S.A.P.P.) or approved equal. The Contractor shall jYa add approximately 10 pounds of dispersing agent per 100 gallons of water in the well. 3. Air-lift swab development shall proceed from the top of the screen to the C bottom of the screen. 4. The double swab shall be raised and lowered several times every 15 minutes. Simultaneously, water shall be lifted with air inside the drill pipe. The pumping rate shall be maximized by using sufficient air pipe submergence and a compressor of sufficient capacity. a. At a minimum, a compressor rated at 600 CFM and 250 PSI shall be required for the Production Well. The pumping rate shall be between 350 and 600 gpm for the Production Well. The pumping rate for the Nested Monitoring Well shall be between 15 and l 30 gpm. After the water becomes free of sediment and there is no more movement of the gravel pack, the swab shall be lowered to the i. next interval. 1 Division III-26 ;t F