Johnson Drilling Co.                                                  Hours of Operation                     
                  23489 E. Kings Canyon                                                 7:00 to 5:00 M-F
                 Reedley, California 93654                                                 (except holidays)
                       (559) 787-2888  
                                          
                                             HOME PAGE                  HISTORY

                                                Services and Service Areas

                          Johnson Drilling Co. drills domestic, irrigation, municipal, industrial, 
                                             and water quality depth sampling wells.


   HARDROCK & CASING DRIVEN WELLS
   Johnson Drilling Co. is capable of many types of drilling.  We drill hardrock wells in the  
   mountain  areas, casing driven wells in the valley and we are one of the few companies capable of drilling
   in cobble rock in the river bottoms.  Many times a well needs more than one type of drilling (casing
   driven and hardrock) to finish the well to the required depth.

   Our general drilling area for irrigation, domestic and municipal wells is the east side of
   Highway 99 encompassing Friant, Millerton, Prather, Auberry, Shaver Lake, Wonder Valley,
   Squaw Valley, Miramonte, Kings Canyon National Park, Reedley, Sanger, Clovis, Fresno,
   Dinuba, Orosi, Orange Cove, Visalia, Porterville, Woodlake, Exeter, Three Rivers,
   Elderwood and Lemoncove.


   UNDERREAMING, TUBEXING or ODEXING
   Johnson Drilling Co. is one of the few drillers capable of this process.  The underreaming method
   allows the driller to advance an outer casing along with the drilling bit. This method allows for completion
   of the annular seal and screened sections through loose (running) decomposed rock and cobble.  An
   outer casing is carried along as the drilling progresses until it can be landed in consolidated formation. 
   After landing the casing, wings on the bit are retracted and the drill-string assembly pulled.  This casing
   can then be perforated with a down-hole air perforator and the inner casing, with perforations at
   selected locations, is installed.  The space between the two casings is filled with gravel-pack material
   except for the upper 20 to 50 foot which is completed by placing a bentonite annular seal.  The ability to
   deal with these difficult saturated zones of highly weathered rock accounts for the majority of
   successful water wells in the Shaver Lake and river bottom areas.


   WATER QUALITY DEPTH SAMPLING
   The objective of a casing hammer method test well is to enable collection of information on 
   subsurface geology, water production potential, and vertical variations in water levels and quality
   at different depths.  Water samples are collected from approximately one dozen depths.

   The casing hammer method is used to drill and drive casing.  The procedure consists generally of
   installing 6-5/8" diameter steel casing as the drilling proceeds and airlifting the water from various 
   water bearing strata as they are encountered.

   After the shallowest zone to be sampled is reached, the driller continues to drill and case the test hole
   until a clay or other fine grained stratum is encountered.  The casing is landed in that stratum and the
   drilling continues through it into an underlying sand or gravel stratum.  Water is then airlifted to the
   surface for a minimum of fifteen minutes.  Sufficient air pressure is provided to lift the water. 
   This test procedure is repeated at approximately thirty foot intervals as directed by the Engineer. 
   The Engineer then collects the water samples for chemical analysis.

   In addition to the above described test sampling, approximately three depths are selected by the Engineer 
   for pumped samples.  We install a submersible pump and pump the test hole for two hours to obtain
   samples of water.  The water samples are then collected by the Engineer for chemical analysis.

   Upon completion of the test well, the well is abandoned in accordance with applicable provisions of the
   State of California, Department of Water Resources.  The Engineer will use the information
   gained from water quantity and chemical analysis to design a production well.

   Our general drilling area for water quality depth sampling test wells is Merced on the north to
   Bakersfield in the south.


   WELL JETTING AND CLEANING
   We clean wells by injecting air into them and removing any sediment, clay or sand from the bottom. 
   You will have an approximate yield in gallons per minute.  

   We will clean the bottom and work any perforations in order to prolong the life of the well.  Quite
   often this is the only way of knowing whether a well is still usable or if a new one should be drilled.


   PUMP DEVELOPING
   We strongly advise pump developing of all large diameter wells to increase production, reduce sanding,
   and to assist the design of the production pump.