Slotted Liner

A slotted liner is a steel pipe with screen slots cut into the pipe wall. The slots are cut along the length of the pipe, and they typically range in width from 0.020 to 0.250 inches. Slotted liners are manufactured to API 5CT specifications, and they are used in a variety of applications including oil and gas production, water injection, and geothermal wells. One of the key advantages of a slotted liner is that it can provide enhanced performance in high-sand content environments. The slots allow for increased communication between the wellbore and the formation, which can significantly improve hydrocarbon recovery rates. In addition, slotted liners can also be used to achieve zonal isolation in multi-zone completions. By properly selecting the slot size and spacing, it is possible to create a barrier between zones that will prevent fluid mixing and improve production efficiency.

Why choose tuspipe?

Since 1998, Tianjin United Steel Pipe Co., Ltd (TUSPIPE) has been committed to supplying high-quality line pipes.

With over 500,000 tons annual production capacity, the company serves various fields and industries, such as oil & gas exploitation and transmission, ship & auto-building, water & electricity, environmental protection, mechanical engineering, infrastructure construction and etc.

TUSPIPE places a premium on product quality and rigorous product quality control. In order to maintain good product quality, the company has established a Test & Inspection Center since 2004. With a series of state-of-the-art tests and inspection equipment, the test & inspection center is able to perform the tensile tests, hydro tests, impact tests, DWTT, etc.

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Slot Size of Slotted Liner

The slot size of the slotted liner, which includes the width and length of the slot, is customized to the customer’s specifications. The minimum slot width for straight or keystone slots is 0.012 inches, and the maximum slot width is 0.25 inches.

1.5 inches long	2.0 to 2.5 inches long	2.5 inches long
0.012 inch wide	0.024 inch wide	0.078 inch wide
0.015 inch wide	0.025 inch wide	0.125 inch wide
0.016 inch wide	0.038 inch wide	0.250 inch wide
0.018 inch wide	0.048 inch wide	–
–	0.058 inch wide	–

Slotting Patterns of Slotted Liner

Three distinct slot layouts have been created to accommodate distinct traits (shown below). In comparison to staggered and straight slot patterns, the gang slot design significantly improves the liner’s resistance to lateral buckling and collapse stresses.

Staggered Slotted Liner

Staggered slots are evenly distributed around the circumference with an offset.

Gang Slotted Liner

Gang slots are made up of many slots that are dispersed around the perimeter.

Straight Slotted Liner

Straight slotted liner features slot columns spaced evenly around the circumference without offset.

Slot Types of Slotted Liner

TUSPIPE can laser-cut slots to customer specifications, either straight or keystone.

- Straight Slots

This slot type is cut perpendicular to the liner and has the same diameter from the inside to the outside of the wall. While straight slots are less expensive to build, they are less effective in containing sand than keystone slots.

- Keystone Slots

Keystone slots, or tapered slots, are cut at a little angle and are larger on the inside than on the outside, ensuring that any particle entering the slot can pass freely without clogging it.

While keystone slots are more expensive to manufacture than straight slots, they eliminate the danger of production losses caused by filled liner slots.

Slot density

The slot density of a pipe is defined as the number of slots per foot of pipe. It is determined by the pipe’s outer surface’s open area. The open region of a slotted liner has a significant role in diminishing its sand control capacity. In general, open land is between 2% and 4% of the total area.

After determining the open area, slot width, and liner diameter, the slot density per foot can be estimated using the following formula:

N = (12*π*D*C) / (100*W*L)

N stands for slot density or the number of slots per foot
D stands for the outside diameter of the liner in inch
C stands for open area, percentage
W stands for slot width in inch
L stand for the length of the slot in inch

For example, if the open area of a 4.5″ slotted liner is 3%, the slot width is 0.02 inches, and the slot length is 1.5′, what is the slot count per foot?

The required number of slots is shown below using the calculation above:

N = (12*π *4.5*3) / (100*0.020*1.5) = 172

Note: This is a straightforward calculation for a straight slot or a seamed keystone slot.

Dimensions and Sizes of Slotted Liner

- Specification & Size of Tubing Slotted Liner

O. D.

Weight

W. T.

End Processing

Non-upset coupling-thread

Upset coupling-thread

Steel Grade

lb./ft.

H40

J55

L80

N80

C90

T95

P110

2 3/8

2.38

60.3

–

0.167

4.24

–

4.6

4.7

0.19

4.83

PNU

5.8

5.95

0.254

6.45

–

PNU

6.6

–

0.295

7.49

–

7.35

7.45

0.336

8.53

–

2 7/8

2.88

6.4

6.5

0.217

5.51

PNU

–

7.8

7.9

0.276

7.01

–

8.6

8.7

0.308

7.82

–

PLB

PLBE

–

PLB

9.35

9.45

0.34

8.64

–

PLB

PLBE

–

PLB

10.5

–

0.392

9.96

–

PLB

–

PLB

11.5

–

0.44

11.18

–

PLB

–

3 1/2

3.5

88.9

7.7

–

0.216

5.49

–

9.2

9.3

0.254

6.45

PNU

10.2

–

0.289

7.34

–

12.7

12.95

0.375

9.52

–

PNU

14.3

–

0.43

10.92

–

15.5

–

0.476

12.09

–

0.53

13.46

–

102

9.5

–

0.226

5.74

–

0.262

6.65

–

13.2

–

0.33

8.38

–

16.1

–

0.415

10.54

–

18.9

–

0.5

12.7

–

22.2

–

0.61

15.49

–

4 1/2

4.5

114

12.6

12.75

0.271

6.88

PNU

–

15.2

–

0.337

8.56

–

0.38

9.65

–

18.9

–

0.43

10.92

–

PLB

21.5

–

0.5

12.7

–

PLB

23.7

–

0.56

14.22

–

PLB

26.1

–

0.63

–

PLB

P——Plain；N—— Non-upset coupling-thread；U—— Upset coupling-thread； L——Integral

- Specification & Size of Casing Slotted Liner

DN	O. D.		Weight		W. T.			End Machining Form
	O. D.		Weight		W. T.			Steel Grade
	in	mm	lb/ft	kg/m	in	mm	H40	J55	L80	N80	C90	P110
	in	mm	lb/ft	kg/m	in	mm	H40	K55	L80	N80	T95	P110
4 1/2	4.500	114.3	9.5	14.14	0.205	5.21	PS	PS	–	–	–	–
			10.5	15.63	0.224	5.69	–	PSB	–	–	–	–
			11.6	17.26	0.250	6.35	–	PSLB	PLB	PLB	PLB	PLB
			13.5	20.09	0.290	7.37	–	–	PLB	PLB	PLB	PLB
			15.1	22.47	0.337	9.56	–	–	–	–	–	PLB
5	5.000	127	11.5	17.11	0.220	5.59	–	PS	–	–	–	–
			13	19.35	0.253	6.43	–	PSLB	–	–	–	–
			15	22.32	0.296	7.52	–	PSLB	PLB	PLB	PLBE	PLB
			18	26.79	0.362	9.19	–	–	PLB	PLB	PLBE	PLB
			21.4	31.85	0.437	11.1	–	–	PLB	PLB	PLB	PLB
			23.2	34.53	0.478	12.14	–	–	–	–	PLB	–
			24.1	35.86	0.500	12.7	–	–	–	–	PLB	–
5 1/2	5.500	139.7	14	20.83	0.244	6.2	PS	PS	–	–	–	–
			15.5	23.07	0.275	6.98	–	PSLB	–	–	–	–
			17	25.3	0.304	7.72	–	PSLB	PLB	PLB	PLBE	PLB
			20	29.76	0.361	9.17	–	–	PLB	PLB	PLBE	PLB
			23	34.23	0.415	10.54	–	–	PLB	PLB	PLBE	PLB
			26.8	39.88	0.500	12.7	–	–	–	–	–	–
			29.7	44.2	0.562	14.27	–	–	–	–	–	–
			32.6	48.51	0.625	15.88	–	–	–	–	–	–
			35.3	52.53	0.687	17.45	–	–	–	–	–	–
			38	56.55	0.750	19.05	–	–	–	–	–	–
			40.5	60.27	0.812	20.62	–	–	–	–	–	–
			43.1	64.14	0.875	22.22	–	–	–	–	–	–
6 5/8	6.625	168.28	20	29.76	0.288	7.32	PS	PSLB	–	–	–	–
			24	35.72	0.352	8.94	–	PSLB	PLB	PLB	PLBE	PLB
			28	41.67	0.417	10.59	–	–	PLB	PLB	PLBE	PLB
			32	47.62	0.475	12.06	–	–	PLB	PLB	PLBE	PLB
7	7.000	177.8	17	25.3	0.231	5.87	PS	–	–	–	–	–
			20	29.76	0.272	6.91	PS	PS	–	–	–	–
			23	34.23	0.317	8.05	–	PSLB	PLB	PLB	PLBE	–
			26	38.69	0.362	9.19	–	PSLB	PLB	PLB	PLBE	PLB
			29	43.16	0.408	10.36	–	–	PLB	PLB	PLBE	PLB
			32	47.62	0.453	11.51	–	–	PLB	PLB	PLBE	PLB
			35	52.09	0.498	12.65	–	–	PLB	PLB	PLBE	PLB
			38	56.55	0.540	13.72	–	–	PLB	PLB	PLBE	PLB
			42.7	63.54	0.625	15.88	–	–	–	–	–	–
			46.4	69.05	0.687	17.45	–	–	–	–	–	–
			50.1	74.56	0.750	19.05	–	–	–	–	–	–
			53.6	79.77	0.812	20.62	–	–	–	–	–	–
			57.1	84.97	0.875	22.22	–	–	–	–	–	–
7 5/8	7.625	193.68	24	35.72	0.300	7.62	PS	–	–	–	–	–
			26.4	39.29	0.328	8.33	–	PSLB	PLB	PLB	PLBE	PLB
			29.7	44.2	0.375	9.52	–	–	PLB	PLB	PLBE	PLB
			33.7	50.15	0.430	10.92	–	–	PLB	PLB	PLBE	PLB
			39	58.05	0.500	12.7	–	–	PLB	PLB	PLBE	PLB
			42.8	63.69	0.562	14.27	–	–	PLB	PLB	PLB	PLB
			45.3	67.41	0.595	15.11	–	–	PLB	PLB	PLB	PLB
			47.1	70.09	0.625	15.88	–	–	PLB	PLB	PLB	PLB
			51.2	76.19	0.687	17.45	–	–	–	–	–	–
			55.3	80.3	0.750	19.05	–	–	–	–	–	–
8 5/8	8.625	219.08	24	35.72	0.264	6.71	–	PS	–	–	–	–
			28	41.62	0.304	7.72	PS	–	–	–	–	–
			32	47.62	0.352	8.94	PS	PSLB	–	–	–	–
			36	53.57	0.400	10.16	–	PSLB	PLB	PLB	PLBE	PLB
			40	59.53	0.450	11.43	–	–	PLB	PLB	PLBE	PLB
			44	65.48	0.500	12.7	–	–	PLB	PLB	PLBE	PLB
			49	72.92	0.557	14.15	–	–	PLB	PLB	PLBE	PLB
9 5/8	9.625	244.48	32.3	48.07	0.312	7.92	PS	–	–	–	–	–
			36	53.57	0.352	8.94	PS	PSLB	–	–	–	–
			40	59.53	0.395	10.03	–	PSLB	PLB	PLB	PLBE	–
			43.5	64.73	0.435	11.05	–	–	PLB	PLB	PLBE	PLB
			47	69.94	0.472	11.99	–	–	PLB	PLB	PLBE	PLB
			53.5	79.62	0.545	13.84	–	–	PLB	PLB	PLBE	PLB
			58.4	86.91	0.595	15.11	–	–	PLB	PLB	PLB	PLB
			59.4	88.4	0.609	15.47	–	–	–	–	–	–
			64.9	96.58	0.672	17.07	–	–	–	–	–	–
			70.3	104.62	0.734	18.64	–	–	–	–	–	–
			75.6	112.5	0.797	20.24	–	–	–	–	–	–
10 3/4	10.750	273.05	32.75	48.74	0.279	7.09	PS	–	–	–	–	–
			40.5	60.27	0.350	8.89	PS	PSB	–	–	–	–
			15.5	67.71	0.400	10.16	–	PSB	–	–	–	–
			51	75.9	0.450	11.43	–	PSB	PSB	PSB	PSBE	PSB
			55.5	82.59	0.495	12.57	–	–	PSB	PSB	PSBE	PSB
			60.7	90.33	0.545	13.84	–	–	–	–	PSBE	PSB
			65.7	97.77	0.595	15.11	–	–	–	–	PSB	PSB
			73.2	108.93	0.672	17.07	–	–	–	–	–	–
			79.2	117.86	0.734	18.64	–	–	–	–	–	–
			85.3	126.94	0.797	20.24	–	–	–	–	–	–
11 3/4	11.750		42	62.5	0.333	8.46	PS	–	–	–	–	–
			47	69.94	0.375	20.24	–	–	–	–	–	–
			54	80.36	0.435	8.46	–	–	–	–	–	–
			60	89.29	0.489	9.53	–	–	–	–	–	–
			65	96.73	0.534	11.05	–	–	–	–	–	–
			71	105.66	0.582	14.42	–	–	–	–	–	–
13 3/8	13.375	339.73	48	71.43	0.330	8.38	PS	–	–	–	–	–
			54.5	81.1	0.380	9.65	–	PSB	–	–	–	–
			61	90.78	0.430	10.92	–	PSB	–	–	–	–
			68	101.19	0.480	12.19	–	PSB	PSB	PSB	PSB	PSB
			72	107.15	0.514	13.06	–	–	PSB	PSB	PSB	PSB
16	16.000	406.4	65	96.73	0.375	9.53	PS	–	–	–	–	–
			75	111.61	0.438	11.13	–	PSB	–	–	–	–
			84	125.01	0.495	12.57	–	PSB	–	–	–	–
			109	162.21	0.656	16.66	–	P	P	P	–	P
18 5/8	18.625	473.08	87.5	130.21	0.435	11.05	PS	PSB	–	–	–	–
20	20.000	508	94	139.89	0.438	11.13	PSL	PSLB	–	–	–	–
			106.5	158.49	0.500	12.7	–	PSLB	–	–	–	–
			133	197.93	0.635	16.13	–	PSLB	–	–	–	–
P——Plain；S——Short-thread；L——Long-thread；B——Buttress thread；E——Extreme thread

Features of Slotted Liner

A slotted liner is a steel pipe with continuous, precision-cut slots along its entire length. The slots are cut using a high-pressure water jet and can be oriented horizontally or vertically. Slotted liner is manufactured in compliance with API 5CT standards and is available in a range of sizes, from 2-3/8″ to 4-1/2″. The number and size of the slots can be customized based on the application, but they are typically between 0.020″ and 0.250″ wide. The thickness of the steel pipe ranges from 3.18 mm to 16 mm.

The slotted liner has a number of features that make it an attractive choice for well-completion and sand control applications. The slots allow for improved flow performance and increased sand retention, while the steel pipe offers high resistance to corrosive fluids. Additionally, a slotted liner can be run on coiled tubing or jointed pipe, making it a versatile option for a variety of operations. A slotted liner can also be easily removed and replaced if necessary. When selecting a slotted liner for your operation, it is important to consider the desired flow rate, fluid properties, production profile, and allowable pressure drop. With proper selection and installation, a slotted liner can provide many years of reliable performance.

Applications of Slotted Liner

Slotted liners are well screens with perforations or slots that allow the passage of fluid while preventing the passage of sand and other particulates. They are used in a variety of applications, including well completion, well rehabilitation, and sand control. Slotted liners can be made of steel, stainless steel, aluminum, or plastic, and are available in a variety of sizes and slot configurations. In well completion, slotted liners are used to provide a path for fluid flow and to prevent the wellbore from collapsing. In well rehabilitation, slotted liners can be used to increase production by creating new wellbores or by restoring damaged wellbores. And in sand control, slotted liners are used to prevent the production of sand from wells. Slotted liners are an important tool for oil and gas production, and their applications are continuing to expand.