This paper analyzes the safety risks in the process of oil well fracturing, combs the key links of safety management, and puts forward the corresponding safety management countermeasures.

Keywords: oil well fracturing; Risk analysis and safety countermeasures

introduce

Oil well fracturing has many equipment and links, high technology content, difficult construction, harsh working environment, difficult rescue and escape, and difficult safety management, which can easily cause heavy casualties and property losses. This paper analyzes the safety risks existing in the process of oil well fracturing, and puts forward the corresponding safety management countermeasures.

1, risk analysis of fracturing construction

1. 1 fracturing operation well site, with highly concentrated personnel and equipment, generally covering an area of about1600m2; Fracturing equipment includes fracturing truck, sand mixer, instrument truck, manifold truck, sand tanker, vertical sand tank and large tank. Under special circumstances, such as wells with high pressure or large displacement, fracturing trucks and instrument trucks should be added. The well site is densely populated with personnel and equipment, which is difficult to manage.

1.2 Well site layout is prone to hidden dangers. Due to the restriction of the well site, the construction vehicle is too close to the wellhead, and the fracturing instrument vehicle, other auxiliary vehicles and instruments are too close to the high pressure area, which has potential safety hazards.

1.3 dangerous high-pressure fracturing operations in the construction process, especially old wells, repeated fracturing wells and large-scale acidizing fracturing, have complex procedures and the ground pressure is between 30 MPa and 60 MPa, which are easy to cause engineering accidents such as wellbore structure damage, pipeline burst, pipe sticking, sand plugging, pipe string fracture and wellhead equipment leakage, and are easy to cause blowout accidents and falling objects accidents.

1.4 rescue and escape difficulties. Due to various vehicles and fracturing tanks in the well site, the field of vision is narrow. Once an accident happens, it is difficult to escape and get rescue quickly, and it is easy to escalate into an adverse event.

1.5 high environmental protection requirements. If fracturing is out of control, fracturing string breaks or high-pressure wellhead and pipeline leak, fracturing fluid, toxic and harmful gas and crude oil are easy to leak, polluting the atmosphere and surface layer, resulting in major ground pollution accidents.

2. Key links of safety management

2. 1 Operation personnel management should provide well control training for designers, and construction personnel should wear labor protection articles and hold relevant certificates, while non-post personnel should be confined to high-pressure areas.

2.2 Management of production equipment Before using fracturing equipment, ten systems, such as pneumatic control system, hydraulic system, suction and discharge system, instrument and actuator system, and equipment fault diagnosis system, must be carefully checked, and the instrument should be corrected.

2.3 Management of well site layout The well site layout of fracturing construction should be strictly divided into high-pressure area, low-pressure area, wellhead area and auxiliary area, and a warning line should be set up to prohibit non-working personnel from entering. All production equipment for oil well fracturing must be parked upwind and keep a distance of 30m from the wellhead.

2.4 Management of pressure test process The wellhead shall be firmly fixed with wire rope, and the pressure relief valve and safety valve shall be installed on the high pressure manifold. Empty the pressure test and hold it for 15 minutes. Carefully check whether there is perforation and leakage before exhausting. Determine the maximum pressure limiting pressure. Overpressure operation is prohibited in site construction, and emergency stop should be made in case of overpressure.

2.5 Construction process management The construction process mainly includes circulation, pressure test, trial extrusion, fracturing, proppant, displacement, backwashing or moving pipe string, etc. During fracturing construction, the on-site operation command should be unified, and the construction design requirements, downhole conditions, ground equipment and technical conditions of each post must be clearly defined, and various safety measures should be implemented. In the production process, it is necessary to save the relevant materials of safety production, mainly including the roster of operators, work logs, training records, accident and dangerous situation records, safety equipment maintenance records, etc.

2.6 Safety management regulations and safety management of standard oil well fracturing operations must comply with SY6443-2000 Safety Regulations for Fracturing and Acidizing Operations and other relevant safety management regulations.

3. Security countermeasures

3. 1 standardize people's safety behavior

(1) Hold a safety meeting before fracturing to ensure that all on-site personnel know the fracturing construction procedures, and all on-site personnel should know their responsibilities in fracturing construction and the treatment measures in case of emergency. According to the statistics of the number of people on the construction site, the escape route of personnel in emergency is clear, and personnel without construction tasks should be on standby at the designated location when fracturing.

(2) Employees are the main body of oil well fracturing operations, so we should strictly select and appoint fracturing employees from the perspective of caring for employees' lives and protecting productivity. Standardize safety behaviors, strengthen safety education and operation skills training, so that they can operate in their posts according to regulations and standards, reduce human operation errors and reduce accidents caused by unsafe behaviors.

③ During fracturing construction, it shall be carried out in strict accordance with the requirements of operating procedures, and the well site that does not meet the safety requirements shall not be operated. Lifting the high and low pressure manifold, merging the fracturing truck into the manifold, sand dumping truck and other key processes. There must be a special person to command, so as to improve the accuracy and reliability of operation and effectively avoid casualties.

④ It is necessary to eliminate harmful factors in the working environment and create a suitable working environment, thus reducing the possibility of human error.

3.2 Unsafe state of control equipment and facilities

① Production facilities for fracturing operations, according to the construction pressure-resistant grade, determine the selection of oil well fracturing production facilities and professional equipment, and pay special attention to the management of equipment operation inspection, regular calibration, daily maintenance, maintenance and transformation, and scrapping treatment. It is an important way to ensure the safety of oil well fracturing operation to prevent equipment from running with disease.

② Safety inspection is a process of monitoring the non-conformity between the company's production and operation and national, local and enterprise standards, a method of finding hazardous factors and an important content of safety management. Through safety inspection, master the safe operation of oil well fracturing production equipment to ensure production safety.

③ The fracturing equipment at the well site should be arranged in strict accordance with the standards and equipped with complete fire-fighting facilities to eliminate the potential danger of mechanical equipment and chemicals at the fracturing site.

(4) regularly check the safety accessories of the equipment, timely replace or repair the safety accessories that do not meet the safety standards, and eliminate potential safety hazards in operation.

⑤ According to the results of safety inspection and hidden danger investigation, hidden danger evaluation and classification, the safety management department puts forward hidden danger management scheme and organizes its implementation.

3.3 Pay special attention to safety management and emergency rescue.

(1) The oil well fracturing operation unit shall, in accordance with the relevant national laws, regulations and standards on safety production and in combination with the actual production and operation of the unit, formulate various rules and regulations on safety production management of the unit, revise or improve them in time, and organize employees to learn and train new systems.

(2) The fracturing operation unit should establish a safe production management mode suitable for the production development of the unit, establish and improve the safety management network, and equip with safety engineers, which will play a good role in improving the safety management level of the unit and improving the safety production support capacity of the unit.

③ Do a good job in emergency rescue. After the accident, emergency rescue can effectively reduce casualties and property losses. Oil well fracturing operation units shall establish and constantly improve emergency rescue plans to support oil well fracturing operations, strengthen emergency drills, improve emergency technology for accident handling, and reserve sufficient emergency materials and equipment. At the same time, establish a reliable communication and alarm system, strengthen information communication and exchange with brother emergency rescue agencies, ensure timely rescue in case of emergency, and avoid heavy casualties and property losses.

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