How to Drill a Well

A lot of people ask us exactly how we go about drilling a well. We hope that this page sheds a little light on the subject.

The equipment that we use in the LS200 drilling rig that was developed by the late Harry Westmoreland at Lone Star Bits and is now manufactured by the Little Beaver Corporation. The drill rig is a portable machine that can be used to drill many wells (about 50 before it needs to be reconditioned) and is in use worldwide on water ministry projects with Living Water International and Lifewater International, two water well mission organizations. The LS200 is a lightweight machine designed to drill up to 200 feet in soil and soft rock, but we have drilled as deep as 300 feet. It cannot drill through hard rock for more than a few inches. We carry the drill rig in a specially built 5 ton service truck, but it can be carried in a pick-up truck or on a trailer.

The first step is to determine where we will drill the well. We are drilling wells to support churches, school and camps on small sites, so our options for placement of the wells are usually limited. Also, the wells are drilled in soil or soft rock, so a geologic study to locate the well is not needed. However, we do review topographic maps, and nation-wide geologic and hydrogeologic maps prior to drilling. The most useful information usually is from hand-dug wells at or near the drill site. Our primary criteria for well placement is to maximize the distance from the well to the nearest septic system. We also want to place the well up-hill from the septic system. A distance of at least 50 meters is preferred.

The LS200 is a "mud rotary" type drilling rig, which means that it uses a drilling fluid, or "mud" to flush the soil cuttings from out of the hole and to cool and lubricate the bit. The mud also serves the very important functions of holding the hole open and limiting the amount of fluid lost into the soil. The drilling fluid is stored in "mud pits" and is pumped through the drill rod by the mud pump. The general layout of the equipment is shown in the drawing below.

The following photos show the drill rig itself, and some of the details of a project.

New LS200 Drill Rig on Display

The LS200 in action drilling the well in Yrybucua

Mud pits, mud pump and drill rig

150 feet of drill rod laid out ready for drilling

Drill bits are used at the end of the drill rod to cut the soil and advance the hole. We can drill 5 feet in 5 to 30 minutes with a blade bit in sand, or it may take 15 to 30 minutes to drill 5 feet in sandstone with a roller cone bit.

Blade bit for drilling in soil

Roller cone bit for drilling in soft rock

The first step is to dig the mud pits and fill them with water. We usually get water by filling three 55-gal. drums that are in the back of the Toyota at the nearest creek or pond - it takes around 50 drums of water to drill a well. The kids really like helping with this duty. We then add bentonite to the water to get it to the right viscosity. Then the drill rig and mud pump are set up, and everything checked out.

Filling the drums with drill water

The well is drilled by the drive motor turning the rod, with drill bit attached, while the mud pump pumps the the drilling mud through the hollow drill pipe. After the hole is advanced 5 feet, the rod is unscrewed, the motor lifted up and another pipe threaded on. Then the hole is drilled 5 feet deeper. This process is continued until the desired depth is achieved. In new locations where we are unsure of the geology, we drill a 4" pilot hole to a depth of about 100 ft. below the local water table (as determined by nearby hand-dug wells). Next we ream out the hole to the 6" final diameter so that we can set the 4" diameter well casing pipe.

Drillers adding another 5 foot drill rod

As the hole is drilled it is very important that a drilling log be kept of the rate of penetration, hard or soft zones and that soil samples be collected every 5 feet. In addition, the properties of the drilling mud need to be tested and modified as needed. Linda is in charge of keeping all the notes and she is also the "mud engineer".

Linda checking her soil samples.

The Mud Engineer at work

Drilling is muddy, tiring work, but we often thank God that this is what He allowed us to do at this point in our lives. Imagine - a few years ago Linda was trying to convince her database clients that "backing up the computer really is a good idea" and Ed was filling out financial reports to put the best light on the quarterly earnings report of the large engineering firm that he worked for. Now we are....

....playing in the mud in Paraguay - and ...

..drinking terere with the locals.

We never leave the drill rod and bit in the hole overnight for fear that the hole may collapse, trapping the bit - DISASTER. So, "tripping out of the hole" each afternoon and going back in the next morning is part of the process. On a recent hole we drilled 300 ft. and this process took almost 2 hours in the morning and 2 hours in the afternoon - in slow drilling sandstone (30 minutes per 5 ft. rod). So we wound up working very long days just to get in some drilling time.

Even Linda gets to pull some rods

While we are drilling the final depth of the hole, we get everything laid out to build the well. This is important since once we stop circulation of drilling mud and pull the rods, there is danger of the hole collapsing - so we want to be ready to put the well casing in right away. Also - Linda paints the water tank while we are drilling.

300 feet of 4 inch diameter PVC casing ready to put in the well

The bottom 40 to 60 feet of the well casing is slotted to allow the water to enter - this section is called the screen. We usually use a 0.010" slot width.

The PVC casing comes in 20 foot sticks ...

... is glued with a liberal coat of PVC cement

Once the casing is set we flush out the drilling mud with "fresh" water (relatively speaking, since we get the water from a nearby creek or pond). Then we place a coarse sand around the screen to serve as a filter, then place a seal of bentonite to prevent surface water from entering the screened zone, then backfill with the soil that we took out of the hole. We then cement the top 3 to 5 feet of the hole and pour a small slab around the well casing to further prevent surface water contamination.

Bailing out the muddy water ...

... and then inserting the pump.

The final step is setting the pump and cleaning out the well. We usually bail out the well first to remove all of the really muddy and sandy water using a tripod, rope and bailer. Then we set the 4 inch electric submersible pump to finish the process.

Completed well head (with pump installed)

Once the pump is set we can finish cleaning out the well - this may take as long as two weeks, depending on the flow rate and the geologic formation. But - Praise the Lord - they always clear up and the Pastor's family and the congregation are always so pleased to have the gift of abundant, clean water - straight from a tap!!

The water starts out muddy ...

... and then clears up at last!

Antonio LOVES getting water from his spigot!!

Ministerio Agua de Vida