SY/T 5587.5-1993 Conventional well repair operations for oil and water wells - Sand exploration and sand flushing procedures for oil and water wells
Some standard content:
Petroleum and Natural Gas Industry Standard of the People's Republic of China SY/T5587.5—93
Routine repair and merging of oil and water wells
Operation procedures for sand exploration and sand flushing of oil and water wells
Published on September 9, 1993
China National Petroleum Corporation
Implementation on March 1, 1994
1 Subject content and scope of application
Petroleum and Natural Gas Industry Standard of the People's Republic of China Routine repair and merging of oil and water wells
Operation procedures for sand exploration and sand flushing of oil and water wells
SY/T 5587.5—93
This standard specifies the construction design, operation procedures, quality control, data collection and safety requirements for sand exploration and sand flushing of oil and water wells. This standard applies to the construction of sand exploration and sand flushing of sub-oil and water wells for repair and merging. 2 Reference Standards
SY/T5587.6 Oil-water lifting routine repair and operation procedures for pulling and lowering oil pipes 3 Terminology
A method of injecting liquid into the well at high speed, flushing the sand at the bottom of the well by hydraulic action, and using the carrying capacity of the liquid circulation to bring the dispersed sand to the surface.
3,2 Sand flushing fluid
The liquid used for sand flushing.
3.3 Forward sand flushing
The sand flushing flows along the sand flushing pipe, and when it flows out of the sand flushing pipe mouth, it impacts the sand plug at a high flow rate. The dispersed sand is mixed with the sand flushing fluid and returned to the surface along the annular space between the sand flushing pipe and the casing. 3.4 Backwashing
The sand flushing fluid enters the annular space between the casing and the sand flushing pipe, flushes the sediment, and the dispersed sand is mixed with the sand flushing fluid and returned to the surface along the sand flushing pipe.
3.5 Positive and negative sand flushing
Use positive flushing to remove loose sand plugging and make it suspended, and then use backwashing to bring the sand to the surface. 3.6 Pipe flushing and sand flushing
Use a small diameter pipe to go into the oil pipe to flush the sand and eliminate sand plugging. 3.7 Gasified liquid sand flushing
When sand flushing wells with low oil layer pressure or leakage, conventional sand flushing liquid cannot be circulated, and a mixed liquid composed of the sand flushing liquid pumped out and the gas pressed out by the air compressor is used for sand flushing. Fei8 Large displacement joint pump sand flushing
When the oil layer pressure is low or the leakage is serious, two or more pumps are used together for sand flushing. 4 Construction design
4.1 Geological plan
4.1.1 The plan must provide accurate well location, layer position, perforation section, liquid production properties, and production dynamics. The location of the fallen objects and the original sand surface in the production layer pressure square and parallel structure wells. When it is required to retain part of the sand column, the depth of sand flushing should be noted. For water-soft formations, low-pressure layers, and high-loss well sections, it must be noted to prevent clay expansion. Wax ball plugging, gasification liquid sand flushing and other construction requirements. 41.2 The sand prevention pipe column structure diagram must be marked for the parallel flushing of the central pipe in the pipe. China National Petroleum and Natural Gas Corporation approved on September 9, 1993 and implemented on March 1, 1994
4.2 Construction design
SY/T 5587,5--93
Write the construction design according to the requirements of the sand exploration surface and sand flushing plan. The format and content of the design book are shown in Appendix A (Supplement). 5 Operation preparation
5,1 Prepare the parallel tools and oil pipes according to the design requirements. 5.2 The displacement of the pump truck should meet the construction design requirements. The hydraulic calculation of sand flushing is shown in Appendix B (Supplement). 5. The sand flushing fluid should have a strong sand carrying capacity and a suitable relative density. It should have good compatibility with the produced fluid of the stratum and should not cause the formation clay to expand. In general, mud flushing should be avoided, and ditch water is strictly prohibited. 5.4 The site should be equipped with 2 to 8 times the volume of the wellbore clean sand flushing fluid. 6 Operating procedures and quality control
6.1 Sand surface exploration operating procedures and quality control
6.1.1 Lift the original well pipe string and lower the pipe string to explore the sand surface. 6.1.2 For sand prevention using metal wire screen pipes, a combined pipe string with flushing pipes should be lowered to explore the sand surface. The use and coordination of the wire screen pipe and the combined pipe string specifications should comply with the provisions of Table 1.
Combined pipe string, mm
Wire wrap screen specifications, mm
Inner diameter of pipe
Inner diameter of oil pipe
6.1.3 When the oil pipe or downhole tool is lowered to 30m from the upper boundary of the oil layer, the lowering speed should be less than 1.2m/min, and the suspended weight is considered to have encountered the surface when it drops by 10~20kN, and two consecutive explorations are carried out. The depth error within 2000m should be less than 0.3m, and the non-exploration error outside 2000m should be less than 0.6m, and the sand surface position should be recorded.
6.1.4 When the combined pipe string with flushing pipe is used to explore the sand surface, when the flushing pipe approaches the sand-proof lead seal or enters the wire wrap screen, it should be lowered while rotating the pipe string, and the suspended weight is considered to have encountered the sand surface when it drops by 5~10kN, and two consecutive explorations are carried out. The allowable error of the depth should be less than 0.6m, and the position of the sand surface should be recorded. 6, 2 Sand flushing operation procedures and quality control
6,2.1 The sand flushing pipe string can be directly used as the sand surface exploration pipe string. The lower end of the pipe string can be connected to an effective sand flushing tool such as a pen tip or a water-powered turbine drill. 6.2.2 The lifting chamber of the sand flushing tail pipe is more than 3m away from the sand surface. After the pump circulation is normal, the pipe string is lowered to flush the sand. The displacement during sand flushing should meet the design requirements.
62.3 Each single flushing must be fully circulated, and the well washing time shall not be less than 15min. 6.2.4 For casing with a diameter of more than 139.7mm (5-inch), positive and negative sand flushing can be adopted, and a large displacement can be used. Before changing to reverse sand flushing, the positive washing should be no less than 30min, and then the pipe string is lifted 6~8m, and it can be lowered after the reverse circulation is normal. 6.2.5 The winch, wellhead, and pump truck are closely coordinated to control the lowering speed according to the pump pressure and outlet displacement. 6.2.6 After continuous sand flushing for more than 6 single roots, the well must be washed for 1 week before continuing to flush. 6,2. When the pump fails and needs to be stopped for treatment, the pipe column should be lifted to more than 10m above the original sand surface and repeatedly moved. 6.2.8 When the lifting equipment fails, normal circulation must be maintained. 2
SY/T 5587.5--93
6,2.9 When serious formation leakage is found during sand flushing construction and the sand flushing liquid does not return to the ground, the sand flushing should be stopped immediately, the pipe column should be lifted to above the original sand surface, and repeatedly moved. Wax ball plugging, large-displacement joint pump sand flushing, gasified liquid sand flushing and other methods can be used to continue. 6,2.10 The outlet displacement of high-pressure self-flowing well sand flushing should be controlled and should be kept in balance with the inlet displacement to prevent simultaneous spraying. 6.2.11 After sand flushing to the bottom (gray surface) or the designed depth, the displacement should be maintained at more than 400L/min to continue circulating. When the sand content at the outlet is less than D,2%, the sand leakage is qualified. Lift the pipe column 20m above the lip, re-explore the sand surface after settling for 4h, and record the depth. 6.2.12 The sand flushing depth must meet the design requirements. 7 Safety requirements
7.1 The pipe column should be lifted and lowered in accordance with the provisions of SY/T5587.6. 7.2 The water hose must be tied with a safety rope during sand flushing, and the circulation line should not be pierced. 7.3 When using gasified liquid for sand flushing, a check valve should be installed between the air compressor outlet and the cement truck, and the return pipeline must be a hard pipeline and fixed.
74 During construction, personnel are prohibited from crossing the high-pressure area. 7.5 The sand flushing liquid must not fall to the ground. It is recommended to use the double-connected tank circulation sand flushing method, see the provisions of Appendix C (reference).
7,6After sand flushing, the sand flushing fluid and sand that have been settled should be treated to meet environmental protection requirements. 8Data collection
8.1Exploring sand surface
a. Time;
b. Method;
c. Suspended weight;
d. Direct entry;
e. Depth of sand surface.
8.2Sand flushing
a. Time;
b. Method;
G. Name, properties, liquid volume, pressure, and displacement of sand flushing fluid;
e. Description of return material and accumulated sand volume;
e. Sand flushing section and thickness;
F. Loss, oscillation volume, and sand ratio at the outlet before the pump; 9. Settling time and depth of sand surface for repeated exploration.
Basic data
Completed well depth
100th phase of production
Cement return height
2. Oil waist marriage
3. Current production status
4. Construction purpose
5. Construction steps
sY/t 5587,5-93
Attachment A
Oil-water mixed sand surface, sand flushing construction design format (supplement)
Casing size × depth
Original artificial bottom
Oil compensation distance
Oil layer well section
Selection of basket mouth period
Liquid level × casing pressure
Actual injection section
Working system
Density
Casing thickness
Water mixed plug surface
Casing compensation distance
Actual injection thickness
Liquid production
Permeability
Daily oil production
Total mineralizationbzxz.net
VI. Precautions
SY/T. 5587,5--93
Designer
Reviewer
Approver
SY/T 5587. 5--93
Appendix B
Hydraulic calculation of sand flushing
(Supplement))
B1 In order for the sand-carrying fluid to bring the sand to the surface during sand flushing, the return velocity of the liquid flow in the well must be greater than the sinking velocity of the sand particles with the largest diameter in the sand-carrying fluid. The recommended velocity ratio is greater than or equal to 2: V=VV.i
That is. V,x22V;
Wherein, V. is the rising velocity of sand particles during sand flushing, m/s: V is the return velocity of the liquid, m/s:
V, is the free sinking velocity of sand in the static liquid, m/s-the minimum liquid flow velocity required to keep the sand rising, m/s. Vx
（B1）
B2When the formation is not leaking, the return speed of the sand flushing fluid is related to the displacement and the cross-sectional area of the return space (when the formation is leaking, the outlet displacement is used for conversion), and the minimum pump displacement during sand flushing is obtained: Qsx=3600AVyx
Where: Qs-the minimum displacement required for sand flushing, m\/h; A-
-the cross-sectional area of the return flow of sand flushing, m\.
B3During the sand flushing process, the time required for sand particles to rise from the bottom of the well to the surface is calculated according to (3). H
Where: t-the time required for sand particles to rise from the bottom of the well to the surface, s; (B2)
(B3))
H-depth, m.
The free settling velocity of quartz sand with a relative density of 2.65 in water is shown in Table B1, and the free settling velocity of quartz sand in oil is shown in Table B2. B4
Average particle
Descending in water
Free settling speed of quartz sand with density of 2.65 in waterAverage particle
Descending in water
Average particle
Descending in water
SY/T 5587.5—93
Table B2 Free settling speed of quartz sand in oilCrude oil temperature 'C
Crude oil viscosity
Descending speed of coarse sand
cm/min
Sand settling speed
cm/min
Crude oil viscosity
Descending speed of coarse sand
cm/min
Additional instructions:
SY/T 5587,5--93
Appendix C
Double-connected tank sand washing process
(reference)
1 Water hose, 2-swing elbow: 3-lifting card, 4-lifting device: 5-Christmas tree cross: 6-oil flow line: 7-oil pipe pen tip: 8-matching surface: 9-liquid supply tank: 10-cement truck: 11-export hose: 12-sedimentation tank, 13-connecting hose: 14-water supply pipeline
This standard is proposed and managed by the Oil and Gas Production Professional Standardization Committee. This standard is drafted by Shengli Petroleum Administration Downhole Operation Company. The drafters of this standard are Yang Yuanzhong and Qiu Yida.
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