Over the last several years HydroLOGICA has strived and struggled to develop a representative organizational model of drilling water wells in developing countries with applied technical excellence and demonstrated results.
Applied Technical Excellence is nothing more than a fancy way of saying that things are done correctly, the first time, every time. It doesn’t mean that mistakes aren’t made, many are made. It doesn’t mean that there is no failure, there are failures. What it does mean is that wells are located, drilled, constructed, developed, and pumped using the correct equipment, with trained staff who have the right tools and spare parts to properly fix things when they break. Mistakes and failures are documented, talked about, and then processes are developed to ensure that the same mistake is not made twice. Furthermore, it is being done in a very difficult location- Nicaragua; one of the poorest countries in the western hemisphere.
The Oil & Gas Sector demonstrates applied technical excellence all the time, all over the world, in more difficult locations, and while drilling more complicated wells. Comparatively, the Water Access Sector in developing countries is plagued with failure after failure. Resources are wasted, organizations are frustrated, communities are left without water and stakeholders are often found finger-pointing at one another for the failures.
Over the last year HydroLOGICA has successfully drilled four wells next to where other drillers had previously failed attempting to drill a borehole for communities or community projects. At each of the four locations HydroLOGICA succeeded in drilling a well in the same location as the failed attempt. This paper will attempt to analyze the likely causes of the previous failures and articulate what HydroLOGICA did differently to achieve success. Most importantly the paper will discuss the lessons learned from the failure and success, in hopes that it can be applied to future work by other organizations. At its core water well drilling in developing countries is:
“Be successful with equipment in a remote location.”
The success is based on three main principles:
- Qualified and trained personnel
- Correct equipment and tools
- Sufficient materials and supplies (consumables) & access to spare parts
This paper is not meant to shame other organizations in their attempt at similar projects. Most organizations have pure motivations for increasing water access to rural communities. In an effort to protect people and organizations, names have been purposely omitted. A better understanding of the reasons for failure and the results of applied technical excellence is the principle purpose of this paper.
Nicaragua is the largest country in Central America situated in the center of Central America between Costa Rica and Honduras, with both Pacific and Caribbean coastlines. It is home to nearly 6 million people who live in a landscape of mountains, volcanoes, lakes and coastal plains.
In the 1700s, the Spanish colonized the Pacific coast, and in 1821 Nicaragua gained its independence from Spain. The most recent civil war lasted two years from 1978-1979 and resulted in the ousting of the Somoza family dictatorship by the Sandinista guerrillas as part of a larger socialist movement that was sweeping through Latin America. However, conflict continued for the next decade as the US, during the Reagan Administration, financed former Somoza army members, the Contras, to combat the recently elected Sandinista government in the now infamous Iran-Contra Affair. The impact of these wars, as well as damage from natural disasters that included a 1972 earthquake in the capital city of Managua and major hurricanes in the 1990’s and 2000’s, can be seen in the still recovering economy and infrastructure. Nicaragua currently (2018) ranks in the lowest third (126 out of 189) of countries on the human development index with only Honduras and Haiti ranking lower in the western hemisphere.
Out of Nicaragua’s population of 6.2 million people, 3.7 million people live in urban areas (59%) and 2.5 million people live in rural areas (41%). Nicaragua is the largest country in Central America, covering 130,370 square kilometers. It borders Costa Rica to the south and Honduras to the north, with the Caribbean Sea to the east and the Pacific Ocean to the west.
Access to adequate safe water, sanitation, and hygiene are essential to human development and health. However, according to the most recent survey 37% of the rural population still lacks access to improved drinking water which represents over 900,000 individuals.
HydroLOGICA exists to see communities gain access to clean water, develop a working model of applied technical excellence, and demonstrate to the sector that technical excellence is possible even in a challenging context.
HydroLOGICA desires to see world-class quality services that create the necessary infrastructure to support economic development as well as reduce the number of rural communities lacking access to clean water.
HydroLOGICA sites a well using a variety of methods:
- Portal: HydroLOGICA, in partnership Northwater Consulting, developed an online portal where a rapid assessment of any georeferenced location in Nicaragua can be reviewed to determine baseline probability of groundwater.
- Physical site visit: Next a location is evaluated topographically. This involves nothing more than looking at the terrain to identify surface depressions and geological formations that can be indicative of subsurface fracturing.
- Geophysics: HydroLOGICA can then execute Seismoelectric Geophysical studies using an AquaLocate GF6.
- Hydrogeological studies: Additionally, HydroLOGICA partners with Northwater Consulting in support of site reviews, geophysics and larger hydrogeological investigations.
HydroLOGICA is equipped with a 2017 Atlas Copco (now Epiroc) TH10LM with the capacity to drill air to depths of 300 meters (1000 feet) with an Atlas Copco 1,100 Cubic Feet per Minute 300 psi compressor. Additionally, the rig can drill mud to depths of 200 meters (650 feet) with a 300 gpm 145 psi Mission Magnum I centrifugal mud pump. The TH10LM can drill boreholes ranging in diameter from 5 ¼ inches to 12 ¼ inches. HydroLOGICA has 5, 6 and 8 inch hammers with bits ranging from 5 ¼ inches to 12 inches, as well as drag bits and roller cones ranging from 5 ¾ inches to 12 ¼ inches. HydroLOGICA is also equipped with support equipment including a downhole camera, a pump hoist, a Flattank and several small pickup trucks.
Figure 1- 2017 Atlas Copco TH10LM
Figure 2- AquaLocate GF6 seismoelectric equipment
The first well is located in the colonial city of Granada. HydroLOGICA drilled the well in late September of 2019. The well was commissioned by a partnership between the community and two Non-Government Organizations (NGOs). One of the NGOs is globally known and has extensive experience in water access projects. The onsite supervisor, an engineer by education, had little understanding of drilling methods nor well construction. The community committee, who had paid for a portion of the well was also part of the supervision.
Figure 3- Mixing Mud Before Drilling
Figure 4- The City of Granada
Gathering information about previous failures is difficult for a variety of reasons. The full story as to what happened during the drilling attempt is not always accurately described. The first attempt to drill a well was attempted by an unknown local driller whose was only able to drill 33 meters when his bit broke and the community was told he couldn’t continue because of this. It is difficult to draw any conclusions about a broken bit at 33 meters. The failure was likely due to an equipment failure resulting from incorrect equipment or poorly maintained equipment and tools.
The second well was drilled within 5 meters of the first well. The well was drilled by a more reputable driller and the well was successfully drilled to 122 meters. The well was cased with SDR26 PVC with a collapse pressure rating of 160 psi. The well had a static water level of 40 meters. There was an estimated net pressure at total depth of 134 psi. The casing was severely damaged at 44 meters and a total depth of 105 meters was observed due to complete obstruction from either another casing failure or debris from the original failure at 44 meters. At the depth of collapse, at 44 meters, the net pressure on the casing should have been approximately 86psi, which would meet a safety factor of two times the rated pressure. HydroLOGICA was told the casing was damaged while extracting a pump after the pump test. Thus the well was damaged beyond repair and unusable.
Figure 5- Casing damage at 44 meters
Figure 6- Inspecting the with a down-the-hole camera
The well is located on a small plot of land on the outskirts of town across the street from the main cemetery. This small parcel of land is owned by the community and was given as the only option for siting the well. Two previous failed attempts were located within 10 meters of the well drilled by HydroLOGICA. No geophysical study was completed as the community nor NGOs had the ability to change the drill site. Based on the previous failed borehole estimated depth and static water level were known.
Given the known geology of predominantly soft, potentially collapsing formations, mud rotary was selected as the drilling method. Drilling started with a 10 5/8 inch drag bit. The formation was soft from 0 to 75 meters at which point a consolidated confining layer was encountered. The bit was changed to a 10 5/8 inch roller cone and drilling continued. At 80 meters, as the consolidated formation ended, complete loss of circulation was experienced in the next formation. All of our drilling fluid (approximately 1,200 gallons of fluid) was absorbed into the formation. Due to the lost circulation, no cuttings were recovered so we can only make educated guesses as to the lithology of the lost circulation formation.
Attempts were made to seal out the lost circulation formation that included the use of lost circulation material- Diamond Seal, N-Seal and Hole Plug. Momentary circulation was recovered several times, but as drilling progressed through the lost circulation material, full circulation was re-lost.
After conversations with HydroLOGICA’s geologist and US based partner geologist, the decision was made to drill “blind” as the current formation was likely water bearing. The well was successfully drilled blind to 91.4 meters at which point significant bit binding occurred, increasing the risk of a stuck bit. The well was terminated at 91.4 meters. We were told that the second well drilled to 122 meters was drilled with a cable tool, so lost circulation was not a factor.
The well was cased and screened with SDR17 6 inch PVC, and gravel packed. After developing the well it was sealed with 20 feet of cement grout.
The well was developed with an airlift and then pumped with an electric submersible pump. The well was producing over 200 gallons per minute with the airlift for a 7 hour period.
The community and NGOS were responsible for pump installation. HydroLOGICA was told that the plan was to install a 5 horse power / 90 gallons per minute motor and pump.
With little knowledge of the principal reasons of the first two failures only generalities can be made. Principle reasons for failure likely included:
- Trained staff- Using the correct drilling method, installing the correct casing
- Proper Equipment & Spare Parts- Having equipment that was fit for use- inspected and maintained
- Materials & Supplies- Using quality materials seems to have made the difference between multiple failure and success.
- HydroLOGICA has had previous problems with a local supplier of PVC, often receiving orders of casing that was crooked, bell housings of different lengths and well as PVC pipe that was previously stored in direct sunlight for prolonged periods of time.
The second well is located in the small community of El Tamborcito (the little drum). In December of 2019 HydroLOGICA drilled a 91.4 meter well. The well was situated on a local Church property 30 meters from a previously drilled well that was dry.
Figure 7- Air Drilling
Figure 8- The community of El Tamborcito
From what we were told from the original driller, the well was drilled to a maximum depth of 61 meters, and the driller did not have additional drill string. Thus the well was cased and developed, but dry. Several hand dug wells existed in the area but were extremely low yielding, producing less than 25 gallons per day.
The well was sited based on a geophysical survey to identify the location with the highest probability of success and an estimated depth of 91 meters.
The well was drilled to 91.4 meters with air and a tricone bit based on reports from the previous driller and known information about the local geology. The first water strike was at 71 meters. No complications were encountered while drilling.
The well was constructed with 300 feet of 4 inch SDR 26 PVC casing, with screen placed from the first water strike to total depth. Net pressure at total depth was calculated at 142psi.
The well was developed with an airlift until the water was clear and free of fine grain sediment, and then pumped with an electrical submersible pump. The well was producing 10 gallons per minute with 40 meters of drawdown.
The pump was installed by the community and local municipality based on estimated yields taken during development.
- Proper Equipment- In this case the biggest difference between the existing dry well and the well drilled by HydroLOGICA was equipment capacity. The driller has a small trailer rig with a maximum drill depth and drill string of 61 meters.
The third well was located in a community farm managed by a NGO located in the community of Valle de Los Morenos. HydroLOGICA originally did a geophysical study for the NGO to locate the best well on the property. Then the NGO, with their own equipment, attempted to drill the well, but ultimately failed. The NGO then contracted HydroLOGICA to redrill the well.
Figure 9- Adding Drill Sting
Figure 10- The farm of Valle de Los Morenos
The first attempt to drill the well was by the NGO with their own equipment- a 70s era T4 drill rig. According to the driller they drilled 115 meters with air (unknown if by a rotary or down hole hammer drilling method) and then switched to mud because they believed that they were going to encounter water and wanted to drill the water bearing zone with mud. The driller had less than three years of drilling experience and even less experience drilling with mud. The driller introduced the entire drill string into the dry borehole and then began filling the hole with drilling fluid. At some point circulation was lost and they could no longer pump mud. They were able to extract several pieces of drill rod ultimately leaving somewhere around 100 meters of drill rod and a bit completely stuck in the borehole. They failed to recover the drill sting and bit and it was left in the ground.
Based on information known from HydroLOGICA’s previous drilling experience in the area and reviewing the drilling of the 380 feet of the failed borehole HydroLOGICA drilled air rotary with a 10 5/8 inch tricone. At 9 meters the hole started to collapse over the bit due to a soft and unstable sand formation. HydroLOGICA, at that point changed mud rotary to stabilize the borehole and continued drilling the following day. HydroLOGICA drilled with mud to 122 meters. An airlift was done to see if the well was producing water. The well was producing small amounts of water at 122m (about 5 gallons per minute) so the borehole was deepened to 152 meters per the organizations request to increase production.
The well was cased with 6 inch SDR 17 PVC, gravel packed, and had a static water level of 107m. There was an estimated net casing pressure of 247 psi at total depth. The casing is rated to a working pressure of 260 psi.
The well was developed with an airlift and then pumped with an electric submersible pump. The airlift produced 35 gallons per minute and was pumped at 25 gallons per minute.
The NGO planned to do their own pump test and install their own solar pumping equipment.
Based on information collected from the drillers of the first failed well and HydroLOGICA’s experience in drilling the second well at the same location failures include:
- Trained Staff – Lack of proper drilling methods, equipment, and trained staff were the primary reason for failure.
- It is unclear why the staff believed it was necessary to change from air to mud when they encountered water
- The well was drilled with air in a collapsing, unconsolidated formation
- The borehole was filled with drilling fluid after the bit was at total depth. It should have been filled from the surface and drilling fluid circulated as drill string was introduced.
The cost to the organization was approximately $36,000. In this case the failure was three fold.
- The loss of the well estimated at $16,000USD.
- The loss of the drill sting and bit estimated at $20,000.
- The loss of future drilling capacity due to lack of drill string.
- Equipment Capacity & Working Equipment- The compressor on their rig was undersized for the whole diameter and the mud pump was not functioning properly.
The fourth well is located in the small community of San Martín. An established local NGO had twice contracted out the drilling of a community well. Both attempts failed. HydroLOGICA was contracted, a geophysical study was conducted and a well successful drilled.
Figure 11- Drilling in San Martín
Figure 12- The Community of San Martín
The first failed attempt was a well drilled on the side of the road near a 10-15 meter embankment that led down to a natural ravine. According to the community the driller said that there were boulders in the formation falling in on his bit.
In the second attempt to drill, it is unclear if a well was attempted with the same or a different driller. The driller also stated that boulders were falling in and trapping his bit.
The well was drilled at the location recommended by the survey. Based on a review of the predominant geology air rotary or DHH would have been the obvious choice, but based on the two previous failures (possible boulders) HydroLOGICA started drilling with mud to maintain a more balanced borehole. Drilling started with a 8 ½ inch drag bit. Drilling continued to 80 feet where the rate of penetration slowed significantly and the bit was changed to a 8 ½ inch mill tooth roller cone. Drilling was terminated at the desired depth of 61m. Excellent cutting samples that indicated the presence of water were collected from 40 to 43m and from 55 to 61m.
The well was constructed per the organization’s request using 4 inch SDR 26 PVC. The screen was set from 39m to total depth to capture the zones with the best cutting samples. The estimated net casing pressure was 48psi at total depth, 1/3 of the rated working pressure of the PVC. A gravel pack was placed in the screened annular space and a bentonite seal was placed above the gravel pack.
The well was developed with an airlift and pumped with an electric submersible pump. During the airlift the well was producing an estimated 100+ gallons per minute. The well was pumped for water clarity with an electric submersible pump.
Pumping equipment was to be installed by the local NGO.
It is difficult to determine what the principal failure was on the first two drilling attempts. HydroLOGICA did not encounter any boulder type formations, any unstable formations or anything similar. The well drilled by HydroLOGICA was within 100 meters of both failed locations. The geology was the same.
- Trained Staff- HydroLOGICA believes that the driller was inexperienced and in an attempt to explain the problem, told the community incorrect information. The likely cause of failure was a lack of trained staff. No boulders were encountered on would be part of the local geology. No complex drilling methods or equipment were used. The well was very simple to drill.
The author has over 10 years of experience working in the water access sector, implementing drilling programs and training drillers on a global level. Failures are all too common, even ubiquitous, in the world of water well drilling in developing countries. Below are major contributing factors to failure outlined in the four previously discussed wells, representative of what has been consistently observed over the past ten years:
As noted at La Prusia, Valle de Los Morenos, and San Martín untrained drillers lead to failure.
- Not only do they lead to failure, but often times untrained drillers incorrectly diagnose the problem leading to unnecessary future costs.
- Untrained drillers have little or no knowledge of local geology and its relevance to the selection of a drilling method, drilling equipment, drilling materials and supplies.
- Untrained drillers put at risk not only the well being drilled but also the equipment being used.
As noted in the La Prusia and San Martín wells untrained supervisors cannot adequately supervise drilling operations, leading to failed wells.
- Untrained supervisors cannot identify untrained drillers.
- Regardless of their education, a supervisor needs to understand the basics of water well drilling, equipment capacities, materials and supplies to be used and confirm that what was contracted, what is being said, and what was actually done all matches up.
As noted in La Prusia and El Tamborcito the right equipment is necessary to drill a well successfully.
- However, if a well is not started with the correct equipment then it is failed from the start.
- Drillers often don’t use or have access to the correct drilling method, bits, and or properly sized equipment.
- The correct equipment doesn’t mean bigger is always better. In rural water development, access is always an issue and there is a need for small rigs. But, the rig needs to have sufficient drill string, air volume, mud pump capacity, and the correct drill bits to drill the well.
The HydroLOGICA difference
- Qualified and trained personnel
One of the challenges that HydroLOGICA has faced is finding and retaining qualified and trained hydrogeologists and drillers. Training staff correctly takes a huge investment in both time and resources. To train and become qualified, HydroLOGICA sent non-English speaking staff to intensive English language school. English is the global language and for staff to be able to interact with vendors, suppliers and trainers a command of the English language is necessary. Additionally, in most developing countries trade specific training is difficult or impossible to come by. Hydrogeologists and Drillers were sent to the US for drilling and equipment specific training. It is estimated that one year’s worth of salary was invested over a three year time period in each staff member. Additionally, the drill rig manufacturer sent staff to Nicaragua for rig acceptance and rig use training.
- Correct equipment and tools
As discussed previously, the right tool for the job is imperative. Based on a review of Nicaragua’s geology at a country level and taking into consideration types of formations, known depths to water, and likely aquifer yields as well as existing road infrastructure, a drill rig and trucks were selected that best matched the country profile.
Not one drill rig can drill every well. HydroLOGICA selected a rig that could drill both air and mud and drill to moderate depths and diameters. Trucks were selected based on local availability of parts and service and then oversized to handle rugged terrain.
Drilling specific tools such as casing elevators, lifting bails, drill bits and drill rods were all imported. Tools and equipment that could be purchased and/or fabricated locally were purchased in country.
Drill bits were purchased for every formation type from 5 ¼ ich to 12 ¼ inch. Hand tools and fabrication tools and equipment were purchased so a self-sustaining operation at the shop and in the field is possible.
- Sufficient materials, supplies (consumables) and access to spare parts
The local supply chain was reviewed for availability of materials, supplies and spare parts. What was not available locally at reasonable prices was imported. One 40 foot container a year of drilling consumables has been sufficient to support operations.
HydroLOGICA was created to demonstrate a working model of applied technical excellence in water well drilling in developing countries. Technical Excellence is possible; one need look no further than the oil sector. What Oil & Gas knows how to do, HydroLOGICA is now demonstrating; by having well trained staff, following correct procedures, and using the right equipment, tools, and spare parts in order to contribute toward solving the world water crisis.
What HydroLOGICA has learned over the last several years of drilling water wells in Nicaragua and providing training and consulting in the Latina American region and Africa is that there is no “one size fits all” solution. Process need to be sufficiently ridged enough to produce repetitive results yet flexible enough for staff to contextualize their operation. Geology changes from region to region. Regulations change from country to country. And, existing supply chains differ at the local and regional levels.
What HydroLOGICA is demonstrating is that qualified and trained staff, with the right processes, can themselves correctly apply technical excellence to any setting and adapt the model to their context. Applied technical excellence in water well drilling is a series of processes, with the right equipment, that leads to being successful wells. The following graphic represents the simple, yet time tested model:
How to be successful with equipment in a remote location
Figure 12- Technical Excellence Process Chart
As shown above, the building blocks in each of the three phases of Technical Excellence in water well drilling are:
- Qualified and trained personnel
- Correct equipment and tools
- Sufficient materials and supplies (consumables) & access to spare parts
What the water sector needs to do is:
“Be successful with equipment in a remote location”