Services

Hydro-Geological Survey

Prior to Borehole Drilling, a hydro-geological survey is carried out that involves understanding the origin, flow, storage and quality of groundwater within the area, this entails Geophysical assessment, interpretation of Remote Sensed Imagery, different thematic maps. A geophysical investigation utilizes geophysical parameters of the earth to understand the behaviour of the subsurface i.e. Electrical Resistivity hence Electrical Method which is currently preferred based on its accuracy and efficiency in the Basement complex that covers much of the region. A latest Resistivity meter (SSR-MP1-AT) is used for Geophysical surveys. With a professional team of hydro-geologists with over 20years of active experience in Groundwater exploration, our success rate is maximised.

Hydrogeological Investigation

Borehole sittings was carried out by taking into consideration results of the desk studies, reconnaissance and community interests.

Borehole Drilling

This involves boring in an attempt to abstract groundwater for various purposes based on the client such as small and large diameter boreholes, Jagan drilling is fully equipped to handle all types of drilling in any geological conditions.

Air Rotary Drilling

It involves the circulation of air through the drill pipe to cool the spinning drill bit. this method is adopted in areas with consolidated rock formations such as the basement complex.

Mud Rotary Drilling

In this method the circulant is mud or water mixed with polymer, its adopted in areas of unconsolidated rock formations such as in the sedimentary areas.

Borehole Construction

This involves boring in an attempt to abstract groundwater for various purposes based on the client such as small and large diameter boreholes, Jagan drilling is fully equipped to handle all types of drilling in any geological conditions.

Well design

The design of the wells ensure that screens are placed against the optimum aquifer zones.Two well Designs exist ie Shallow well Design(Unconsolidated Rock formations & Large Diameter wells) and Open Hole Design (Consolidated rock formations).

Casing installation

UPVC Permanent casings of up to a maximum of 14 inches can be undertaken, this includes both plain and screened casings, the screened casing are slotted according the national standards.

Gravel pack

This is aimed at minimising the silting from within the wall of the well, the grain size of the gravel pack should be within the range of 2 to 4mm, and granules should be well rounded. Over 95% should be siliceous.

Well Construction

Gravel pack should be sealed off at the top and bottom with clay cement (2m). In this case it is also recommended to install a 3m long, cement grout to prevent contamination (bacteriological as well as industrial) from entering into the borehole.

The remaining annular space should be backfilled with inter material (drill cuttings may be used), and the top six meters should be grouted with cement to ensure that no surface water at well head can enter the well bore and thus prevent contamination.

Well Development

Development aims at repairing the damage done to the aquifer during the course of drilling by removing clays, silts and other additives from borehole walls. Secondly, it alters the physical characteristics of the aquifer around the screen and removes the fine particles.

Surge and block method are highly recommended for the start of the development then followed by constant air lift till the water is considered to be out of silts and high turbidity.

Apron Construction

The mould is designed based on national standards and client’s choice of preference. In South Sudan a mix ratio of 3:2:1 is preferred. The major purpose of this is to protect the borehole from contamination and environmental protection.

Test Pumping

This is aimed at determining the sustainable abstraction rates, design drawdown, pump installation depth and other important well and aquifer parameters such as transmissivity, Hydraulic conductivity, specific capacity among others. Also enables further cleaning of the water out of silts, colour and Turbidity. Three main methods are utilised during test pumping i.e. Constant rate test, Step test and recovery test. During A constant rate test, the pump is inserted 3m below the last screened/aquifer zone and pumped for a designed period of time while observing its drawdown.

A step test is undertaken to enable determination of the proper rate to be pumped constantly. The minimum duration of the constant test should be 03 hours of test pumping, followed by recovery test 95% of the total drawdown has been regained.

Pump Installation and Supply

Depth of installation of the pump is dependent on the Dynamic water level obtained during the constant rate test and also the recovery rate of the well. A minimum sustainable yield of 500 liters/hour for hand pumps and 1500litres/hour for production are recommended for installing a submersible pump in a borehole.
A step test is undertaken to enable determination of the proper rate to be pumped constantly. The minimum duration of the constant test should be 03 hours of test pumping, followed by recovery test 95% of the total drawdown has been regained.

Different models of pumps are available;

  • Hand Pumps
  • Electrical submersible pumps
  • Solar Pumps
  • Hybrid Pumps

Our pumps are fitted with G.I. (Galvanised Iron), S.S (Stainless steel) or the most current on the market PVC which are quality assured by ISO. Different models are available such as Lorentz,Grandfos ,Texmo this pumps are operated by one phase and three phase of 240-210 and 400-380volts respectively.

Consultancy Services

For all groundwater needs from inception to final installation of borehole with handpumps, solar or electric pumps, site investigations. Jagan Drilling SS Co Ltd is well staffed with professional to handle all the technical challenges and provide immediate solutions and advice. An informative detailed report is the final piece that shall be availed to the clients at a timely period.