Standard Operating Procedures and Key Points for Drilling Construction Operations

Standard Operating Procedures and Key Points for Drilling Construction Operations

Drilling construction is a rigorous technical engineering process. Following standardized operating procedures and mastering key points are crucial for ensuring well quality, construction safety, and cost control. Standardized procedures are not rigid dogma, but rather a transformation of practical experience into clear, executable, and verifiable steps. A complete process typically includes four stages: preparation, drilling, well completion, and finishing. Each stage has its own regulations and key points that must be followed.

Stage One: Construction Preparation and Site Layout. This is the foundation of all work, with the key points being "thoroughness" and "safety." The process begins with accurately measuring and marking the well location on-site according to the design drawings. Subsequently, the site must be thoroughly leveled and cleared to ensure a solid, level foundation for the drilling rig, which is crucial to prevent equipment tilting or sinking. The mud circulation pool, material (drill pipes, well casings, filter materials) storage area, and clear safety passages must be planned. All equipment and tools must be inspected and confirmed upon arrival. Proper execution of this stage clears obstacles for subsequent efficient and safe operations.

Stage Two: Drilling and Geological Logging. This is the core stage of the process, with the key points being "stability" and "observation." When starting drilling, a "light pressure, slow rotation" method should be used for a smooth start. Parameters should be gradually increased after the drill bit has penetrated the formation. During drilling, operators must continuously observe and record: changes in drilling pressure and rotation speed, mud return conditions and color, and the rock cuttings samples brought up. This "geological log" is important for determining the location of the aquifer and deciding on the casing plan. Simultaneously, continuous circulation of mud or water must be maintained to cool the drill bit, carry away rock cuttings, and stabilize the borehole wall. Connecting and disconnecting drill pipes must be done according to procedures to ensure safety.

Stage Three: Casing Installation, Gravel Packing, and Well Completion. This is the crucial stage of transforming the "borehole" into a "water well," with the key points being "precision" and "thoroughness." After the borehole reaches the predetermined depth, the mud in the hole must be thoroughly replaced and a preliminary flushing performed. Then, the pre-connected well casing (a combination of screen pipe and solid pipe) is smoothly and vertically lowered into the center of the borehole. Next, the annular space between the well casing and the borehole wall is uniformly and continuously filled with screened gravel (filter material) of appropriate particle size.  Its function is to filter water and prevent sand from entering the well. Following this, powerful and thorough well cleaning must be performed using equipment such as pistons and air compressors until the water flow is stable and the water is clear and free of sand, thus fully activating the well's water production capacity.

The fourth stage: pumping test and final acceptance. This is the final inspection of the well's quality, focusing on "data" and "completeness." After installing the water pump, a continuous pumping test is conducted for several hours, accurately measuring the well's stable water yield and water level drawdown, and collecting water samples for water quality analysis. At the same time, data such as well depth and casing installation depth are verified. All construction records, test data, and acceptance reports must be compiled into a complete archive for delivery. Finally, the construction site is thoroughly cleaned and restored to its original condition. This closed-loop standardized process, from preparation to acceptance, ensures through strict control and recording at every step that the final delivered well is a high-quality project with stable water yield, qualified water quality, and a long service life.