Geothermal wells are a critical underground engineering project, whose quality not only impacts the development and utilization of geothermal resources but also poses severe threats to regional groundwater resources. Therefore, every stage of drilling a geothermal well requires our particular attention. Below is a brief overview of the geothermal drilling process:
One: Drilling Phase: Leveling the site, wellhead confirmation and excavation, foundation construction—installation of drilling equipment—preparation of drilling fluids and other consumables—trial drilling.
Drilling Phase: Construction of the surface casing section, casing running, cementing — technical casing section construction, casing running, cementing — construction of the water extraction target layer section, well logging.
Three: Completion Stage: Slurry flushing with chemicals, combined well cleaning with air compressors—acidification, combined well cleaning with carbon dioxide, and pressure air blowers—water pump water well cleaning.
Level Pipe Installation: Excavation of horizontal pipes, trenching, laying sand in the trench, horizontal pipe construction, backfilling the trench, wetting and compacting the soil after backfilling, ensuring the ground is level after trench backfilling, transporting the slurry and excess soil off-site, constructing waterproof mortar for the inspection well, installing the water separator inside the well, and connecting the pipes. The horizontal main pipe is connected from the inspection well to the machine room, with product protection measures in place.
Groundwater is one of society's vital energy sources. In recent years, as the demand for water resources has continually increased, the development of China's drilling industry has also been rapidly advancing. In the exploration and development of groundwater, many new technologies are required, with drilling technology being one of them. However, from the current situation, the efficiency of drilling operations in China still has room for improvement, and this is also a major factor contributing to the lower oil production efficiency in our country. This article mainly introduces common technologies in drilling projects and, based on practical experiences, proposes several suggestions on how to enhance drilling efficiency, hoping to be beneficial to the development of China's drilling industry.
In today's era, driven by social and economic development and the advancement of science and technology, China has made significant progress in the exploration and development of groundwater. New technologies and equipment for oil exploration and extraction are continually emerging, greatly enhancing the efficiency of oil development. However, as an important engineering process in the oil development, there are still some issues in China's drilling operations that lead to a low drilling efficiency. Below, I will discuss common technologies in drilling engineering and measures to improve drilling efficiency, merely as a stepping stone for further discussion.
What is Drilling Engineering? Drilling engineering primarily involves exploring groundwater structures, utilizing scientific methods to verify the water-bearing area and reserves, and obtaining accurate geological development data, which serves as an effective basis for water resource development. Therefore, drilling efficiency directly impacts the efficiency of groundwater exploitation.
Generally, drilling engineering is divided into three main steps:
① Pre-drilling Preparation: Ensure comprehensive preparation prior to drilling commencement, including setting the well location, leveling the drilling site, constructing foundations, transporting equipment, installing equipment, and preparing the wellhead.
② Drilling Process: Before drilling, it is necessary to clean the well, then connect the casing strings, followed by raising and lowering the drill bit, cementing the well, logging, and well logging. During this process, attention must be paid to making the wellbore larger for the first drilling, using technical casing in the lower layer if encountering complex formations during the second drilling, and pre-designing the casing for three or more drillings. The total number of drilling times should be determined based on the actual conditions.
③ Completion and Oil Testing: After drilling, the oil layer must be fractured, during which effective monitoring of the pressure between strata pores should be conducted, and a scientific design of drilling density, along with the rational application of relevant equipment, is required.
