CATERING THE DEWATERING NEEDS
On construction and mining sites, groundwater can be a major obstacle in achieving safe, efficient, and cost-effective excavation. To overcome this obstacle, companies often opt for the dewatering process. Dewatering is known to be the process of dealing with groundwater to allow excavations to be carried out in workable dry conditions.
Bore and Bore, a company well known throughout Pakistan for their services is proud to claim to be an expert in catering to the issues of companies related to dewatering at their site. One of the key clients of Bore and Bore in the area of dewatering is SECMC. SECMC; a joint venture between the Sindh government and six private sponsors, including Engro Energy, Thal LTD., Habib Bank Ltd., HUBCO, and two Chinese companies CMEC and SPIC, is operating the biggest coal mine in the country.
To cater to the needs of SECMC in the field of dewatering at Thar Block II, Bore and Bore along with the officials of Grundfos leading suppliers of Submersible Pumps, visited their official site to inspect the area and discuss the ways to cater to the need of dewatering challenged by SECMC and to carry out a thorough inspection of the working conditions of their wells and pumps and also report on measures to follow to avoid any problems.
Bore and Bore arranged a visit of the Company Head of Grundfos Pump; Mr. Muhammad Arar on request of SECMC to find a way out to help SECMC for their ongoing operations of dewatering through Submersible Pumps. To follow out the activity of dewatering at Thar, Bore and Bore procured 39 Submersible Pumps from Grundfos suppliers or Grundfos Dealer to ease out the operations.
Bore and Bore, along with Grundfos supplies have a team of highly skilled people to cater to the needs of dewatering throughout Pakistan. Furthermore, Bore and Bore is also available on the platform of Grundfos to follow out work of not only dewatering but of drilling of tubewells, operation and maintenance of plants, and many more.
BNB consolidate is the market leader in Hydrogeological and Geotechnical sectors of Pakistan. Our team of highly motivated engineers and geologist help drive BNB towards our goal of market leadership through the use of innovative methods and advance instrumentations. Bore and Bore, established in 1990 as a trifling drilling company with less number of drilling rigs is now providing and expending its services in all Geological sector i.e. Hydrogeological study, Geo-Technical investigation, Geophysical sector and Topographical mapping throughout Pakistan.
In these 3 decades of long journey, Bore and Bore struggled progressively and faced hurdles and losses as well as success and achievements simultaneously. Bore and Bore drilled more than 1000s of shallow and deep-water wells throughout Pakistan in that time period. It established its assets in this era. It started its journey with 2 drilling rigs which are the leading assets of a drilling company. In 1996, Bore and Bore drilled their very first 1000ft water well that stands as the stepping stone for the company and helped BNB successfully extend their assets to a total of 6 drilling rigs and other equipment, becoming Pakistan’s one of the renowned drilling company it is today.
In 2013, Bore and Bore was turned into BNB consolidate with expanding their wings in various Geological services sector. It became a firm providing all Geological services rather than just a drilling company. BNB Consolidate later introduced BNB Engineering as the leading Soil Testing Company in the market. BNB also stands in Geophysical sector and installations of Water Treatment Plants. In this time period, BNB has also installed dozens of R.O plants in different cities of Pakistan; majority in industrial hubs of Karachi and resettlement areas of Thar.
After expanding their list of services, BNB was able to capture the market with various projects all over Pakistan. With the definite time period the assets of the company also increased with now BNB owning 8 different types of drilling rigs including Truck Mounted Heavy Straight Drilling Rigs, Hydraulic straight drilling Rigs, Tripod Straight Drilling Rigs, Reverse Circulation Drilling Rigs, Soil investigation drilling Rigs with different diameter of bit size i.e. 8.25 to 36”.
All these equipment and services allows BNB to provide the one window turn key solutions, which is the essential need of Industry to plan and execute the sustainable projects.
BNB consolidate is the market leader in Hydrogeological and Geotechnical sectors of Pakistan. Our team of highly motivated engineers and geologist help drive BNB towards our goal of market leadership through the use of innovative methods and advance instrumentations. Bore and Bore, established in 1990 as a trifling drilling company with less number of drilling rigs is now providing and expending its services in all Geological sector i.e. Hydrogeological study, Geo-Technical investigation, Geophysical sector and Topographical mapping throughout Pakistan.
In these 3 decades of long journey, Bore and Bore struggled progressively and faced hurdles and losses as well as success and achievements simultaneously. Bore and Bore drilled more than 1000s of shallow and deep-water wells throughout Pakistan in that time period. It established its assets in this era. It started its journey with 2 drilling rigs which are the leading assets of a drilling company. In 1996, Bore and Bore drilled their very first 1000ft water well that stands as the stepping stone for the company and helped BNB successfully extend their assets to a total of 6 drilling rigs and other equipment, becoming Pakistan’s one of the renowned drilling company it is today.
In 2013, Bore and Bore was turned into BNB consolidate with expanding their wings in various Geological services sector. It became a firm providing all Geological services rather than just a drilling company. BNB Consolidate later introduced BNB Engineering as the leading Soil Testing Company in the market. BNB also stands in Geophysical sector and installations of Water Treatment Plants. In this time period, BNB has also installed dozens of R.O plants in different cities of Pakistan; majority in industrial hubs of Karachi and resettlement areas of Thar.
After expanding their list of services, BNB was able to capture the market with various projects all over Pakistan. With the definite time period the assets of the company also increased with now BNB owning 8 different types of drilling rigs including Truck Mounted Heavy Straight Drilling Rigs, Hydraulic straight drilling Rigs, Tripod Straight Drilling Rigs, Reverse Circulation Drilling Rigs, Soil investigation drilling Rigs with different diameter of bit size i.e. 8.25 to 36”.
All these equipment and services allows BNB to provide the one window turn key solutions, which is the essential need of Industry to plan and execute the sustainable projects.
When production is started through a tube well; with that there also arise several technical issues. These issues are majorly related to operation and maintenance of the wells. Siltation process, damaging of casing pipes, pump motor issues are some of the main issues that are raised frequently. BNB designs several solutions for the maintenance of these wells.
These frequent water well issues can be fixed by chemical dozing, compressor washing, pump repairing and tapping of the formation where some crack or cavity is observed, however, for a well to be maintained these solution needs to be followed in proper manner in a particular timeline. The life span of water well is generally calculated through the siltation process of geological formation; with passage of time silt and sand particles choke the gravel pores. In general, the life span of a tube well solely depends on the Operation and Maintenance practices of the well by chemical dosing, back washing and water jetting.
Proper monitoring and maintenance of the tube wells will help predict the upcoming issues and serve in taking necessary actions. The installed submersible pump motor needs to be monitored physically at an interval of every 6 months. Seal and bush of the pump initially malfunctions, so they need to be replaced on time for the pump to work properly. Master Control Unit (MCU) and safety factors of submersible pump should be checked continuously at an interval of 6 months. The dry out sensor installed to prevent the pump from working against dry conditions ensures the water presence and normally gets affected when it is left for too long in the well, resulting in scaling and salt preservation on surface thus, giving out false reading due to which the motor burns out.
The 3M slicing kit; used to form a connection between electrical cable and motor wire has an outer plastic shell with a life of 2 years. In well maintenance steps, it is recommended to inspect the joint every 12 months to prevent any malfunction of joints and cables. Furthermore, in the process of lowering and dismantling of submersible pump, the cable along with it sometime disintegrates due to friction while lowering, resulting in water intrusion in cable’s outer insulation whereas over conductivity between the three phases results in the burn out of the motor, therefore, it is recommended to inspect the cable at every 12 months and replace it when needed.
Drop pipes and pipes joining material i.e. nuts, bolts etc. gets rusted and fused due to the presence of high TDS level in the water, resulting in the fall of drop pipes when they are not properly monitored, so it is recommended to inspect them from time to time and replace if needed. The gaskets (packing sheet) can also eventually bursts if water flow decreases by butterfly valve, blockage caused due to filters, any hurdles faced in discharge of water, when surface of pipes gets rusted or distorted in high frequency or due to reverse polarization of motor during operation.
Another step of well maintenance is the chemical dosing; a treatment with sodium hexa-meta phosphate including all previous steps after every 18 months for 24 hours. To procure sustainable quantity of water it is necessary to rehabilitate the water well after 24 months of well construction. In rehabilitation of well, video logging is an essential step for well maintenance which gives a clear view and condition of the water well. BNB is the renowned company providing the services of video logging for well maintenance. If the video logging result shows the s presence of siltation process in the well then air compressor washing should be done for the maintenance of well.
BNB recommends these well maintenance steps to their overall clientele. It is assured that the clients are satisfied with their well condition and are acquiring their required quantity of water after following through this well maintenance timeline.
The dynamics of earth can be studied on its various physical and mechanical properties like density, velocity, resistivity etc. Tomography is the appropriate phenomenon for the determination of the high resistive and less resistive layers of the earth. Tomography is the best and accurate phenomenon for 2D/3D profiling of the sub-surface of the earth. 2D/3D profiling of the earth provides a 2D/3D model which is obtained by performing tomography on the location. 2D/3D profiling consists of the 2D/3D model which is obtained by a software namely Zondres2 and Res2dinv in which resistivity values at each point is plotted on X-axis and depth is plotted on Y-axis.
Tomography at Jhumpir is performed by BNB for the installation of windmills for the electricity generation. These windmills have too much weight that before installing them, one has to do the fractures/void and stability analysis of the sub surface on which these windmills have to be installed, tomography is the appropriate phenomenon for this purpose which provides high resolution 2D/3D model in which the cavities and structures of the sub-surface is mapped effectively which helps in analyzing the low stable and weak zone of the earth where constructing and installing heavy structures could be hazardous.
Tomography provides a best 2D/3D profiling of the shallow depth investigations of the earth upto 100 m to 150 m. In tomography, an array is set with varying distances of steel electrodes placement which are connected to Polares tomography panel which serve as a current penetrate into the earth with in connection with high voltage battery which provide potential to it. Whereas, steel electrodes deployed at varying distances serves as a current receiver at each distance. BNB stands to be the pioneer in providing 2D/3D profiling services as we are the trendsetter in this domain. Whereas, Attmuqam Hydropower Project also receives tomography services from us as we are a trendsetter in achieving new success horizons in all geophysical domains. We provide 2D/3D profiling with tomography services to major mega projects at national level in Pakistan.
Seismic, the most advanced and latest technology for exploring the hidden treasures of earth. Seismic exploration technique has two methods i.e. Seismic Refraction Method and Seismic Reflection Method. Seismic Refraction Method is one of the most advanced technique for delineating the sub-surface structures, its structural regime, tectonic settings, geological and geomorphological features. Whereas, Seismic Reflection Method is used for delineating the hydrocarbons i.e. Oil and Gas (Fossil fuel) beneath the earth surface. Seismic, basically works on the principle of S=VT by penetrating the sound waves into the earth surface. So, in this regard sound waves can also be inferred as seismic waves. Seismic waves are the very essential source for making a sub-surface image.
At Attmuqam, the dam structure has to be built which serve as the road structure as well, the concerned authorities want to acknowledge the complete sub-surface structural and overburden of formation to place the foundation at main formation. The fastest way to get this job done is to perform the Seismic Refraction Survey, our PASI Seismic Refraction tool stands to be the most authentic, trending and problem solver tool. By means of our Seismic Refraction tool, efficiently handled by our highly qualified Geophysicist solved this riddle. Seismic waves penetrated into the sub-surface with the help of sledge hammer hitting on metal plate, then seismic waves travel into the earth’s layer with varying time period and then these seismic waves receive on the geophones installed on the surface in the form of signals. These signals are recorded in the form of time regime from which the amplitude, velocity and frequency has been easily calculated. Therefore, the earth layers have different velocities and waves travel time, so in order to calculate these parameters all the efforts have been made. Seismic Refraction Method, basically helps in delineating the sub-surface structures, their stability and bearing capacity purely on the basis of variation of Acoustic Impedance contrast encounter on different depths of the earth’s layer. Seismic, is purely based on examining the acoustic impedance contrast of the sub-surface whereas, acoustic impedance contrast is the multiple of two physical parameters of earth i.e. Density and Velocity. Seismic waves when penetrated in to the sub-surface they change their behavior where they encounter the variation in velocity and density of the layers.
On the basis of these recorded parameters in the field, the processing, refinement and interpretation of the data is performed on the geophysical processing suite namely Intersism. Seismic data processing includes several steps for generating a synthetic seismogram. This synthetic seismogram is the ultimate outcome for interpreting the lithology, structural regime, faults, folds, cracks, cavities and stability of the ground.
Attmuqam Project has been accomplished successfully by making these essential majors with our seismic refraction tool and demarcating the overburden with quicker and reliable way. Therefore, seismic refraction is recommended to be conducted on all construction projects like dams, high rise towers, bridges, construction of landing jetties, construction of airport runways, railway tracks, windmills installation, dumping sites, landfill sites etc.
From the spud of borehole till its construction to production, each and every parameter matters to us. Following the suitable steps leading to the successful conclusion, otherwise challenges befalls but in this modern era, technology has certainly reduced the struggles and lessen the failures. Similarly, our industry is not behind in technology and expertly dealing the downfalls with finest engineering options.
Video Logging
Amongst many borehole exploration tools Video Logging Instrument has significant implementation and considered superlative in exploring or having visuals inside the borehole. Hence, not many practitioners in Pakistan are having access to this technology nor have teachings to function with such devices. Video Logging Tool was introduced by BNB in Pakistan back in early 2015. First time, Video Logging Technology applied at Nestle borehole in Port Qasim for Schlumberger, it turned out to be successful, which further helped Nestle to retain the existing well with minor maintenance of borehole.
Hurdles may encounter after the casing has been done. Video logging serves as a problem solver and solution provider to the society regarding its water needs and boreholes development. The factory located in the Lasbela Industrial Development Authority (LIDA) namely as Digital Dyeing Pvt Ltd encountered a problem in its 285 ft deep water well. The video logging is the ultimate solution for the problem as the water producing from this borehole was giving silty water with suspended particles making it useless. Nobody knew what the real problem in the borehole is. Rectification was not possible without identifying the issue. Video logging is the primary initiative for anybody to look upon. Then, they approached BNB for the solution of their problem. Therefore, our video logging equipment stands to be the one most efficient tool in the market for the live monitoring and recording of the current borehole scenario which gives the real time picture of the borehole that what is the problem in the borehole and why it is behaving like this.
Video logging is the source which enables us to counter the main hurdle in the borehole. The borehole casing was damaged badly at the depth of 159 ft having a big crack due to which the silt and formation particles are intruding into the borehole and the water is wholly contaminated with silt and suspended particles. So, video logging is the only source which led to encounter the main problem. Video logging equipment is a portable tool consisting of winch, high resolution camera and necessary tools. All over the Pakistan our video logging services stand to be one of the most reliable and effective borehole hurdles unlocking tool. Like this, our video logging phenomenon sets another milestone also like in Indigo Textile pvt Ltd, Denim E Clothing, H2 Readymix, Thar coal block 2, Shangrila foods, Petaro Nooriabad, US Embassy Islamabad, Lakhani Silk Mills. Our Video logging services serves at various domestic and industrial boreholes.
In Pakistan, video logging is the essential need for water borehole related issues. Whereas, advancement in video logging equipment has led the water industry to solve problems efficiently with more reliability and satisfaction. Video logging is now being used as a bore casing monitor, to find out the static water table in the bore. Water quality of the bore is easily observed by video logging phenomenon. Video logging is also helpful in determining the total depth of borehole.
Bore & Bore drilling and solutions is a renowned well drilling company in Pakistan. Key mission and vision is to attain the largest well drilling company position across the world. Among all the well drilling companies BNB is the emerging well drilling company which provides consulting services within the field of water well drilling, water management and water exploration.
BNB’s major scope as the well drilling company is to serve the best in water exploration. BNB well drilling company works in multi-phase. To begin with we keep up the Coordination between Client and contractor then Preparation of tender document, Bill of quantities, evaluation of drilling contractor, working methodology, Engineering cost estimation. Conducting technical meetings with Client, Consultant and Contractor. Secondly this reputed well drilling company arrange field survey to study the topography of the area. Electrical Resistivity survey to study aquifer characterization, drainage pattern and selection of water well drilling points.
After all the pre requisite examination and routine surveys BNB well drilling company provides Drilling supervision to ensure working methodology, aquifer zoning, soil logging of the hole. Ensure timely completion of work. Inspection of water well materials. Design of water well for maximum yield. Supervise pump out test to ensure safe yield. Selection of pump and its safe yield, Pump setting depth etc.
Finally, BNB water well drilling company Designs a pump room and rehabilitation of existing wells (after sales support). Preparation of water well report based on factual findings and tests is also included.
Not only in water exploration but also in the geotechnical borehole drilling Bore and Bore is serving as the pioneer. BNB well drilling company has a vibrant team of engineers and geologists who are continuously working in laboratory and field to provide accurate and reliable geotechnical and geological data. The engineers and geologists of this well drilling company examine the soil and rock layers that make up the earth in order to determine their physical and chemical properties through drilling of boreholes and laboratory testing. Using this information, BNB designs foundations and earthworks structures for buildings, roads, dams, embankments, cuts, foundations, retaining walls, anchors, tunnels and all other structures directly interacting with the subsoil, both onshore and offshore.
Dewatering is essential to prevent the damage to structure foundations specially in case of high salinity water intrusion regions; therefore, BNB’s respective client Matrix Pharma engage the services of BNB dewatering division to counter the water intrusion issue. On 22nd of December, 2018 BNB started the project of dewatering, to reduce the water level for base foundation construction. BNB had started drilling work on 23rd Dec, 2018 and drilled 50ft. borehole with 8” diameter. The drilling completed on 24th Dec, 2019 and cased the well with 5” diameter across casing. BNB moreover introduced Piezometers, the installation including all works required that installation of two bore holes (at distance 5.0 & 20.0 ft. from production well) of relatively smaller borehole depth (40 ft. each) and dia 4”.
These wells are constructed for measuring water level before and during the pumping through submersible pump of water from production well. After all these processes of well construction on 28th Dec, 2019 installation of submersible pump (2 HP) took place for water quality and quantity. Guide line of 1.5” dia had been placed. This yield test was operational for approx. 48 hours. But this submersible pump was not giving the significant discharge for dewatering as it produced 48 GPM discharge, to mitigate this issue the specialized group of BNB enhanced the efficiency of submersible pump and on 31st Dec, 2018 we installed another submersible pump of 3 HP for increasing discharge. After the upgrade of submersible pump’s efficiency increased the discharge to about 55 GMP. Dynamic Water Level (DWL) within in the pumped well is measured and recorded at a particular time with flow and rechecked after an interval of timings as provided in the recording form. This process was continued till the completion of 48 hours. The Original Static Water Level (OSWL) in the pumped well has been taken after finishing of the activity. The required levels in the production well are measured through a sounder to measure the water level fluctuations (drawdown) in the well. According to the same interval of timings as provided in the recording form, this process of pumping with help of submersible pump was continued till the completion of 48 hours.
This area is near to the Korangi Creek so, the recharge factor is very high and recovery of static water level is considerably high. It is very challenging to sustain the draw down. BNB recommended 33 nos. of borehole with effective submersible pump, which can maintain 70 GMP within construction site with 20’ x-factor, and submersible pump depth should be maintained at 35ft. to 40ft.
After implantation on BNB recommendations with adequate submersible pump sets, BNB’s client successfully able to achieved the dry land targeted depth and place the safe and sound foundation to continue the projected factory building.
Hydrogeological Modelling
Exponential rise of population ultimately increased water demand for domestic as well as industrial needs. This huge consumption leads to the era of groundwater exploration to fulfill all kinds of water necessities. In current scenario it has been observed that borehole water exploration is majorly done in industrial areas than that of residential sectors. This excessive borehole water is pumped through shallow aquifers of Manchar formation due to which borehole water quality is deteriorating continuously in terms of high TDS, turbidity which results in disturbed borehole water chemistry. Such frequent and vast borehole drilling is also the cause of lowering borehole water table day by day. Underground hydrogeology modelling or hydrology is, according to Mikhailov, the science that studies the origin and formation of groundwater, its forms of storage, diffusion, movement, regime and reserves, interaction with soils and rocks, its state ( liquid, solid and gaseous)) and properties. (physical, chemical, bacteriological and radioactive); as well as the conditions that determine the measures of its use, its regulation and its disposal. It is therefore one of the most complex branches of geology.
Moreover, inappropriate recharge from uncontained sanitations, effluents effect, dense population, insufficient fresh water recharge also degrades water quality of shallow borehole water. Being a hydro-geology leading consultant, it is suggested that government of Pakistan should take serious action to secure groundwater resources. As groundwater depletion not only creates water crisis but these high drilling activities also attribute to the instability of the sub-surface in particular localities which triggers minor tremors and jolts, which could probably be upcoming biggest threat to the society in future. To overcome severe water crises in forthcoming decades, government of Pakistan should develop an organized regulatory body, whose target should be to regulate and save borehole water resources in terms of both quality and quantity. It is also the necessity of time to impose strict rules and regulations to reduce the trend of borehole water drilling. For this purpose regulatory bodies should hire services of well-trained geologists to design the scheme and provide their services for betterment. According to these rules, in Karachi industries would be restricted to seal aquifers of Manchar formations from which millions of liters of water is being extracted annually, and continually reducing potential of these aquifers gradually. Now it’s high time to seal upper regimes and target to deeper new regimes of Gaj formation for extracting borehole water resources as it is found to be a confined aquifer and major source of borehole water of the sub-surface, which is still untouched horizon. The need of time to counter the deeper horizons of the earth and target Gaj formation for extracting water resources as it is found to be a confined aquifer and major source of borehole water. Similarly, same phenomenon is suggested for water consumers all over Pakistan at domestic and industrial level. For household purpose, the government policy must be affixed that they can consume sub-surface borehole water from only shallow regimes and perch water levels.
This regulatory body should also propose groundwater recharge policies by Manchar formation by constructing number of small-scale local recharge dams to store significant quantity of rain/fresh water, which would be maintained appropriately on regular basis. As the dam construction is one of the most important major to take by stakeholders for the solution of borehole water needs in future. Certain small water reservoirs have to be constructed in the area near Noriabad and in the locality of Kithar National Park which serves as a natural water storage for the borehole water consumption of our society. Yearly, millions of liters of fresh water has wasted by flowing into the sea, so it’s high time to make such ideal entrapment in mountains which shall serve as a water storage tanks for the society.