Standardized Drilling Operation Procedures

Standardized Drilling Operation Procedures

Drilling is a rigorous engineering activity. Adhering to standardized operating procedures is crucial for ensuring well completion quality, efficiency, cost control, and operational safety. Standardized procedures are not rigid rules, but rather the transformation of best practices accumulated over time into clear, repeatable, controllable, and verifiable steps. A complete drilling process can typically be systematically divided into four main stages: preparation, drilling, well completion, and acceptance.

Stage 1: Construction Preparation and Site Layout. This is the foundation of all work and determines the smooth progress of subsequent operations. The process begins with accurately measuring and marking the well location on-site according to design drawings or pre-planned plans. Subsequently, the site is leveled and cleared to ensure the drilling rig has a solid, level foundation, and mud circulation pits, material (such as drill pipe, well casing, and filter media) storage areas, and safety access routes are planned. All equipment, tools, and materials must be inspected and verified upon arrival to ensure they are in good condition. The more thorough the preparation in this stage, the fewer unexpected interferences will be encountered during subsequent construction.

Stage 2: Drilling and Cuttings Logging. This is the core of the process. When starting drilling, the rig is typically started smoothly with "light pressure and slow rotation," gradually adjusting to normal parameters once the drill bit enters the formation. During drilling, operators must continuously monitor the rig pressure, rotation speed, and mud return, and meticulously record the depth, lithological characteristics, and changes of different formations encountered. This is called "well logging," a crucial basis for determining the location of aquifers and the casing installation plan. Simultaneously, continuous circulation of mud or clean water must be maintained to cool the drill bit, carry away rock cuttings, and stabilize the borehole wall. After each drill pipe is drilled, drilling must be stopped and the pipe reconnected according to the prescribed procedure to ensure operational safety and borehole verticality.

The third stage: casing installation, gravel filling, and well flushing. After reaching the predetermined depth, the critical stage of converting the "borehole" into a "water well" begins. First, the drilling mud in the borehole must be completely replaced and a preliminary flush performed. Then, the pre-connected well casing (a combination of filter pipe and solid pipe) is smoothly and vertically installed into the borehole. Next, carefully selected gravel of suitable particle size (filter media) is evenly filled into the annular space between the well casing and the borehole wall to filter water and prevent sand buildup. Then, a powerful and thorough well-washing operation is performed using a piston, air compressor, or water pump to remove fine particles from the filter media and aquifer until the water output is stable, the water is clear and free of sand, and the well's water production capacity is fully realized.

The fourth stage: Pumping test and final acceptance. This is the final inspection of the well's quality. After the water pump is installed, a pumping test is conducted for several consecutive hours to accurately measure the stable water output at different drawdowns, and water samples are collected for water quality testing. Simultaneously, key data such as well depth and well casing installation depth are verified. All construction records, test data, and acceptance reports are compiled and delivered to the owner. Finally, the construction site is cleaned up to ensure a clean and tidy environment upon completion. This closed-loop process from preparation to acceptance, through standardized control at each step, maximizes the guarantee that the final delivered well is a high-quality well with stable water output, qualified water quality, and a long service life.