Redesign of Hydraulic Pumping Unit at Well Alf-04 Kawengan Field KSO Pertamina PT Sarana Gss Trembul

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Redesign of Hydraulic Pumping Unit at Well Alf-04 Kawengan Field KSO Pertamina PT Sarana GSS Trembul

Adrian Indarti¹, Abdul Kamid², Nurkhozin Adhi Nugroho³and Alfisyahri Nasution⁴

Akademi Minyak dan Gas Balongan

Jenderal Sudirman Street No. 17, Indramayu, West Java, 45212, Indonesia Corresponding author: adrianindarti88@gmail.com, hamied45@gmail.com,

Manuscript received: March 06^th, 2023; Revised: May 04^th,2023 Approved: May 15^th,2023; Available online: May 19^th,2023

How to cite this article:

Adrian Indarti, Abdul Kamid, Nurkhozin Adhi Nugrohoand Alfisyahri Nasution, 2023, Redesign of Hydraulic Pumping Unit at Well Alf-04 Kawengan Field KSO Pertamina PT Sarana GSS Trembul, Scientific Contributions Oil and Gas, v46 (1) pp., 29-37 DOI.org/10.29017/SCOG.46.1.1322.

SCIENTIFIC CONTRIBUTIONS OIL AND GAS

Testing Center for Oil and Gas LEMIGAS

Journal Homepage:http://www.journal.lemigas.esdm.go.id ISSN: 2089-3361, e-ISSN: 2541-0520

ABSTRACT - The methods of lifting fluid from the well to the surface consists of natural wells method and artificial lift method. One type of artificial lifting is Hydraulic Pumping Unit (HPU) method. In this case, well ALF-04 as the HPU well in Kawengan field which faces lower actual production compare to its theoritic production calculation then decided need to be redesianed. The objectives of redesaigned are to reach optimum flow rate of the well based on the calculation of IPR, rod size selection, calculation of peak polished rod load, pump depth and plunger size on the amount of fluid raised.Recently actual flow rate of this well is 309.2 bfpd, and then the result of IPR calculation by Vogel shows the Q max is 957.25 bfpd, it means this production well is still feasible to be optimized till approximately 765.8 bfpd. After redesign, determined pump setting depth 755 m, the plunger size of 2.5 “, 120” stroke length, and speed of 6 spm, pump displacement 568.425 bpd. For the rod diameter was changing from 0.75 inch to 0.875 inch, it greatly affects the maximum stress value of 22,774.03 psi, and also has an influence to the increasing of PPRL value of 8243.26 lb, and the MPRL value of 3000 lb.

Keywords: Hydraulic Pump, Stroke Per Minute, Peak Polished Rod Load, Pump Displacement

INTRODUCTION

Selection of the right artificial lift method is necessary to obtain optimum oil production. One of the artificial lift methods that can be chosen is the Hydraulic Pump Unit method. In the operation of HPU in oil fields, there is often a mismatch problem between the desired production rate (theoretically) and the actual production rate (low pump volumetric efficiency), so an evaluation of the performance of the HPU is needed to obtain optimum pump performance and production results. For that purpose, then it is necessary to attention the condition of the well, Hydraulic Pumping Unit is very suitable for wells that are <1000 m, it is also necessary to attention the flow rate of the well production, the bottom pressure

of the well, and the character of the well fluid, so that the HPU method can operate as expected.

After calculating the IPR using Vogel method for undersaturated oil reservoir, it shows that the production of the ALF-04 well can still be optimized beyond the current actual production, by redesigning the HPU. In theory, the redesign of the HPU aims to increase production or optimize it by taking into account the SL, SPM, well depth, plunger diameter and actual production amount. The ‘’ALF- 04’’ well has an actual production of 309.2 BFPD and the IPR calculation shows that the well’s optimum flow rate is749.86 BFPD, so it still has the potential for optimization. This is what underlies the author of conducting this study.

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Scientific Contributions Oil & Gas, Vol. 46. No. 1, April 2023: 29 - 37

Theory Review Basic Theory

HPU is one type of Pumping Unit. Pumping units are used as an alternative method of artificial lift. The use of a hydraulic pumping unit is carried out because there is not enough gas available in the field, so the gas lift system cannot be implemented. In addition to the method of using a Sucker Rod Pump, there is also a type of pump that works in almost the

Figure 1 Hydraulic pumping units

same way, namely the HPU used at KSO Pertamina PT Sarana GSS Trembul. By selecting the method using the Hydraulic Pumping Unit Artificial Lift, need to attention to what well conditions are in the use of this method. The Hydraulic Pumping Unit is suitable for well conditions with a depth of <1000 m, it is also necessary to attention to the known flow rate of the well bottom so that the Artificial Lift method can be ensured in lifting process.

Standard Tower Telescopic Tower

Figure 2 Artificial lift system

Hydraulic Pump

Submersible Electric Pump

Gas Lift Plunger Lift Progressive Cavity Pump Rod Pump

Puching Anchor Rod Pump

Sucker Rod

Floate Stator r

Hydraulc Pump

Armored Cable

Pump Elecrtic

Motor

Control Equipment

LiftValve Gas

Packer Standing Valve (Optional)

Catcher w/

Arrival Sensor

Plunger Bumper Spring Tubing Stop

Electronic Controller Lubricator

Sucker Rod

Motor

Catcher w/

Arrival Sensor

Sucker Rod

Motor

Catcher w/

Arrival Sensor

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Redesign of Hydraulic Pumping Unit at Well Alf-04 Kawengan Field KSO Pertamina PT Sarana GSS Trembul (Adrian Indarti , et al.)

HPU (Hydraulic Pump Unit)

HPU or Hydraulic piston pump, its systems can lift large volumes of liquid from great depths by pumping wells down to fairly low pressures. Crooked holes present minimal problems. Both natural gas and electricity can be used as a power source. They are also applicable to multiple completions and offshore operations. Their major drawbacks include power oil systems being fire hazards and costly, power water treatment problems, and high solids production being troublesome (Guo : 2006).

HPU Working Principle

The working principle of the HPU nstallation that is :

• Hydraulic fluid high pressure from the power pack is pumped to the hydraulic jack to transmit the pressure from the hydraulic fluid into an up and down motion on the hydraulic jack.

• From the hydraulic movement earlier, it is then forwarded by the polished rod, then the sucker rod and to the plunger, so that the plunger moves up and down, which is a circular motion step of the pump.

• If the plunger moves up (up-stroke), then under the plunger there will be a pressure drop, so that the bottom pressure of the well is greater than the pressure in the pump, this condition causes the standing valve to open and fluid enters the pump.

At the end of the up stroke the volume below the plunger is completely filled with liquid and when the plunger moves down (down-stroke), the standing valve will close because the plunger presses on the fluid, at the same time the fluid will press down on the traveling valve, so that the fluid comes out of the plunger and enters the tubing

• This process takes place repeatedly, so that the fluid in the tubing will move up to the surface and flow towards the separator through the flow line.

Figure 3

Upstroke and down stroke

Advantages of HPU

• It does not require a foundation so it is easy to move from well to another and is simple in technical adjustment.

• Determination of SPM and stroke length is easier, because it does not require replacement of the pulley and does not require heavy equipment to shift the crank pin in determining the stroke

length as in a bouncy pump.

• Optimizing wells with HPU can be done easily and precisely because the parameters of pump speed and steps can be done at any time with a shorter time, so that production losses can be minimized.

• Setting HPU steps is easier because all you have to do is change the Hydraulic settings.

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Disadvantages of HPU

• Not suitable for large production (Q HPU bpd).

• Limited well depth (pump depth <1000m).

• Not suitable for inclined wells.

Damage to the HPU

Damage to the HPU well is caused by sand, rust, and gas problems.

The parts that were damaged include:

• Plunger, the presence of sand or scale on the plunger, resulting in stuck with the working barrel.

• The ball is oval in shape (not round) because of sand, scale and the impact between the ball and the cage wall.

• Working barrel becomes concave/flat.

• The stuffing box leaked when setting the HPU.

• The rod broke because of the corrosive fluid.

Calculation of Well Productivity ALF-04 Productivity Index (PI)

Productivity Index is an index used to express the ability of a well to produce under certain conditions, or expressed as a comparison between the rate of production of a well at a certain price of well bot-

tom flow pressure (pwf) and the difference in well bottom pressure in static conditions (Ps) and bottom pressure well at the time of flow (pwf), expressed in stock tank barrels per day.

The easiest approach to describe the capability of production wells is to use the concept of PI which has been developed with the following assumptions:

• Steady flow (steady state) and the viscosity of the flowing fluid remains constant.

• The stream flowing in a radial well.

• The flow consists of a single-phase incompress- ible fluid.

• The permeability around the wellbore is homo- geneous.

• The formation is completely saturated with flowing fluid.

Inflow Performance Relationship (IPR)

The IPR curve is a curve that describes the ability of a well to produce, which is expressed in the form of a relationship between production rate (q) and bottom well pressure (Pwf).

In preparing for the IPR curve, it is necessary to know the PI of the well, which is a qualitative descrip- tion of the ability of a well to produce.

Figure 4 IPR curve

API 30 API 3S API 45 API 60

0

2000 4000 6000 8000 10000

Qo (bbl/day)

2000 2500 3000 3500

1500 1000 500

PWF

• Single Phase IPR Curve

The IPR curve for one phase will form a linear line with a constant PI value for each pwf price. This happens when the reservoir pressure (Pr) is greater than the oil bubble pressure (Pb). Fluid flow at res-

ervoir pressure is greater than bubble pressure or constant PI and Ps is also constant, so the variables are q and pwf. Pwf and production rate have a linear relationship, called the Inflow Performance Relation- ship, which describes the reactions of the reservoir

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when there is a pressure difference in it.

• Two Phase IPR Curve

Because there is a change in pressure at the bottom of the well, when the pressure at the bottom of the well is below the bubble point pressure (Pb) of oil, the gas that was originally dissolved will be released and turn the fluid into two phases which will form the curved IPR curve.

This shows that the PI will decrease as the production rate increases. This two-phase IPR equation has been developed by Vogel. The Vogel method can be used for pressure conditions above and below the bubble point pressure. The IPR curve above the bubble point pressure will be in the form of a straight line, while for below the bubble point pressure the IPR curve will be in the form of a curved line. In this study, the IPR method was used by Vogel for undersaturated reservoir.Vogel developed equation use assumptions that :

• Gas booster powered reservoir.

• Reservoir pressure below bubble point pressure.

• The skin factor is zero.

• Three Phase IPR Curve

For three-phase IPR, the Wiggins method can be used, for the Wiggins method it is a development of the Vogel method which takes into account the rate of oil and water production.

METHODOLOGY

In writing the final assignment study entitled Redesign of Artificial Lift Hydraulic Pumping Unit at ALF-04 well, the research method used in several chapters as follows.

Introduction

In collecting the data needed in this study, the authors use several reference sources.

Data Collection

The data needed is pump data, namely pump depth, maximum and minimum Stroke Length, maximum and minimum SPM, PPRL, rod size and Plunger diameter. Well data, namely perforation interval depth, well depth, well pressure, static pressure, and fluid level. Production data, namely fluid specific gravity, actual production amount.

Data Processing

Calculating the PPRL produced does not exceed the HPU specification capacity used, calculating pump displacement of fluid that can be pumped to the surface, calculating the stress value that exists on the rod so that it does not exceed the maximum stress limit, during the pumping process.

RESULTS AND DISCUSSION

Redesign of the HPU at ALF-04 well is carried out by setting and readjusting the pump size, SL, SPM, tubing diameter, plunger, determining the ac- celeration on the rod, calculating displacement, and calculating max PPRL on ALF-04 well conditions.

Interpretation of Data and Information

Broadly speaking, the data used in the prepara- tion of this report can be divided into several major sections, namely:

Pump Data

Table 1

Pump and Equipment Data Interpretation

Pump and Equipment Data

Pump Type TH 2.75’’

Type HPU 120’’

Casing Diameter 5’’

Tubing Diameter 2 7/8’’

�arre� Length 3 �

Rod Diameter ¾’’

Rod Length ¾ 1178 m

Rod Length 7/8 1217 m

Rod �eight ¾ in the air 1.63 �b/�

Rod �eight 7/8 in air 2.367 �b/�

Rod Number API 76

Step Length (S) 130 inch

Pump Speed (N) 5 SPM

�arre� Length 3�

Rod Number API 76

Pump and Equipment Data

Pump Type TH 2.75’’

Type HPU 120’’

Casing Diameter 5’’

Tubing Diameter 2 7/8’’

�arre� Length 3 �

Rod Number API 76

�arre� Length 3�

Rod Number API 76

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Well Data

Table 2

Interpretation of Data on Wells

Figure 5 Well Profile ALF-04 Subsurface Data

��tal Well Dept� 2659.1 � (810 m)

Pump Dept� (PSD) 2477 � (755 m)

Sta�c Fluid Level (SFL) 275.83 m

Dynamic Fluid Level (DFL) 364.78 m

��p Per��ra��n Dept� 644 m

��m Dept� Per��ra��n 650 m

�id Per��ra��n Dept� (D) 647.8 m

Spesiﬁc Gravity Oil (SGO) 0.828

Spesiﬁc Gravity Water (SGw) 1

Spesiﬁc Gravity Gas (SG) 0.070

�r��uc�� Data

(Qt)

Water Cut (WC) 95.1%

PwF 1622 psi

Pr 2200 psi

Pb 1817

Subsurface Data

��tal Well Dept� 2659.1 � (810 m)

Pump Dept� (PSD) 2477 � (755 m)

Sta�c Fluid Level (SFL) 275.83 m

Dynamic Fluid Level (DFL) 364.78 m

��p Per��ra��n Dept� 644 m

��m Dept� Per��ra��n 650 m

�id Per��ra��n Dept� (D) 647.8 m

Spesiﬁc Gravity Oil (SGO) 0.828

Spesiﬁc Gravity Water (SGw) 1

Spesiﬁc Gravity Gas (SG) 0.070

�r��uc�� Data

(Qt)

Water Cut (WC) 95.1%

PwF 1622 psi

Pr 2200 psi

Pb 1817

Casing 30’’

377.3 � (115 m) Casing 19 5/8’’

657.5 � (200 m) Casing 13 3/8’’

1907.5 � (581 m) PSD 1937.5 � (755 m)

Perf. Lap 2116.1 – 2132.5 � 644-649 m

MD. 2657.5 (810 m)

Casing 30’’

377.3 � (115 m) Casing 19 5/8’’

657.5 � (200 m) Casing 13 3/8’’

1907.5 � (581 m) PSD 1937.5 � (755 m)

Perf. Lap 2116.1 – 2132.5 � 644-649 m

MD. 2657.5 (810 m)

IPR Curve Analysis Using the Vogel Method To analyze the IPR curve, it is carried out through the stages when the condition is Pr > Pb and Pwf <

Pb. Using the Vogel (Undersaturated oil Reservoir) method and calculating the optimum production rate of the well. Furthermore, the rate of oil production (q) can be determined for various variations in Pwf prices. Calculations that need to be done for undersaturated reservoir include PI, determining the value of Qb, determining the value of q max, determining the value of q at various pwf value when Pwf >

Pb, using the value of q at various Pwf value when Pwf<Pb and the last stage value plots q vs Pwf.

Pwf Value Variations

Table 3 Pwf value variation

YƐƐƵŵƉƟŽŶƉƐŝ YŽƐƐƵŵƉƟŽŶďĨƉĚ

2200 0

2000 164.55

1800 220.1

1600 284.23

1400 342.5

1200 400.7

1000 464.11

800 522.6

600 586.89

400 648.2

200 749.86

0 800

YƐƐƵŵƉƟŽŶƉƐŝ YŽƐƐƵŵƉƟŽŶďĨƉĚ

2200 0

2000 164.55

1800 220.1

1600 284.23

1400 342.5

1200 400.7

1000 464.11

800 522.6

600 586.89

400 648.2

200 749.86

0 800

So, from the results of the calculation of pr>pb, pwf test <Pb shows qob 209.86 and Qmax has a result of 749.86 at ALF-04 Well has an actual Q of 309.2 BFPD in the Kawengan Field.

Determination of Pump Setting Depth

Based on Figure 7, it can be seen that at a DFL altitude of 755 m. The function of the graph is to de- termine the depth of the PSD (Pump Setting Depth).

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Figure 6 IPR Curve

IPR (Pr > Pb, PwF test < Pb)

Qo, bpd

Kurva utk PwF test > Pb Kurva utk Pwf test < Pb PwF, psi

2000 1500 1000 500

0

0 200 400 600 800

Chart Area

IPR (Pr > Pb, PwF test < Pb)

Qo, bpd

Kurva utk PwF test > Pb Kurva utk Pwf test < Pb PwF, psi

2000 1500 1000 500

0

0 200 400 600 800

Chart Area

Q vs DFL

Q(Bfpd)

0 200 400 600 800 1000

0 100 200 300 400 500 600 700 800

DFL 755 m Q = 835,46 bopd

Figure 7 Graph of Q vs DFL

Calculation of Pump Volumetric Efficiency

Table 4

Design calculation result

NAMA HASIL

Luas Permukaan Dinding Plunger 3.97 inch² Luas Permukaan Dinding Top Rod 0.601 inch²

Faktor �ecepatan �a� 0.06 �/s

Berat Rod String 4024.79 lb

Berat Fluida 3759.32 lb

Imfulse Factor 1.06 �/s

Peak Polished Rod Load 8432.26 lb

Minimum Polished Rod Load 3000 lb

Stress Maximum 22,774.03 lb/in²

Stress Minimum 4985.75 lb/in²

Plunger Overtravel 0.63 inch

Luas Pluger 4.9 inch

Perpanjangan Rod ¾ 1684.24 lb

Perpanjangan Rod 7/8 2520.55 lb

Pump Displacement 568.425 Bpd

NAMA HASIL

Luas Permukaan Dinding Plunger 3.97 inch² Luas Permukaan Dinding Top Rod 0.601 inch²

Faktor �ecepatan �a� 0.06 �/s

Berat Rod String 4024.79 lb

Berat Fluida 3759.32 lb

Imfulse Factor 1.06 �/s

Peak Polished Rod Load 8432.26 lb

Minimum Polished Rod Load 3000 lb

Stress Maximum 22,774.03 lb/in²

Stress Minimum 4985.75 lb/in²

Plunger Overtravel 0.63 inch

Luas Pluger 4.9 inch

Perpanjangan Rod ¾ 1684.24 lb

Perpanjangan Rod 7/8 2520.55 lb

Pump Displacement 568.425 Bpd

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Discussion

Based on the results of the Redesign Hydraulic Pumping Unit at ALF-04 Well, the actual production of the well is 309.2 bpd and after calculations are obtained, the Qmax result is 749.86 bpd. With this the production of the well can still be optimized by selecting a Hydraulic pumping unit pump. The size of the rod used is 7/8” and 3/4” in diameter, the selection of this rod affects the stress rod value of 22,774 psi, Stroke Length of 120” and the number

Figure 8

HPU Specifications installed

Figure 9

Screening criteria for artificial lifts

ALS Applica�on Screening Criteria

Form of List �od Li� PCP Gas Li� Plunger Li� Hydraulic

Li� Hydraulic

Jet ESP Capillary

Technology

�� ,

��D (��) 16,000

4,876 12,000

3,658 18,000

4,572 19,000

5,791 17,000

5,182 15,000

4,572 15,000

4,572 22,000 6,705

��

(BFPD) 6,000 4,500 50,000 200 8,000 20,000 60,000 500

�aximum opera�ng

temperature (‘Fi’C) 550°

288° ²⁵⁰°

121° ⁴⁵⁰°

232° ⁵⁵⁰°

288° ⁵⁵⁰°

288° ⁴⁰⁰°

204° ⁴⁰⁰°

204°

Corrosion handling Good to

excellent Fair Good to

excellent Excellent Good Excellent Good Excellent

Gas handling Fair to

good Good Excellent Excellent Fair Good Fair Excellent

Solids handling Fair to

good Excellent Good Fair Fair Good Fair Good

Fluid gravity (*API) >8° ^<40° ^>15° ^>15° ^>8° ^>8° ^>10° ^>8°

Servising Workover or pulling rig Wireline or workover rig

Wellhead catcher or

wireline Hydarulic or wireline Workover or

pulling rig Capillary unit

Prime mover Gas or

electric Gas or

electric Compressor Well’s natural energy �ul�cylinder

or electric �ul�cylinder

or electric Electric

motor Well’s natural energy

��shore applica�on Limited Limited Excellent N/A Good Excellent Excellent Good

System eﬃciency 45% to

60% 50% to

75% 10% to 30% N/A 45% to 55% 10% to 30% 35% to 60% N/A

of spm is 6 steps using a pump/plunger diameter size of 2 ½ “and a pump setting depth of 755 m then the pump displacement results are 568.42 bpd, the maximum weight received by the Hydraulic Pumping Unit is 8670.86 lbs. If we correlate the ALF-04 well with the Screening Criteria Hydraulic Pumping Unit this well is suitable and the Hydraulic Pumping Unit can be used on the ALF-04 well because this well has a depth of 2659.1ft (below the maximum depth of 17.00ft), this well produces 568.42 bfpd (below Maximum Operation Volume 20,000 bfpd).

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Redesign of Hydraulic Pumping Unit at Well Alf-04 Kawengan Field KSO Pertamina PT Sarana GSS Trembul (Adrian Indarti , et al.)

CONCLUSION

Based on the results of the discussion that has been carried out, several conclusions can be drawn as follows :

• At ALF-04 Well, this well has an actual flow rate of 309.2 BFPD. Production potential calculations are carried out through Vogel IPR under conditions Pr > Pb, Pwf Test < Pb and Q max is 749.86 BFPD, it was quite feasible to optimize the production rate.

• After redesign, determined the plunger size of 2.5

“, pump setting depth 755 m , 120” stroke length, and speed of 6 spm, pump displacement 568.425 bpd. The parameters that affect the amount of fluid that can be lifted are the stroke length (SL) and the pumping rate.

• After changing the the rod diameter from 0.75 inch to 0.875 inch, it greatly affects the maximum stress value of 22,774.03 psi, and also has an influence on the PPRL value of 8243.26 lb, and the MPRL of 3000 lb.

ACKNOWLEDGEMENT

I would like to express our deepest gratitude to Allah SWT, and I wish to extend my sincere thanks to Mr. Abdul kamid, Mr. Nurkhozin Adi Nugroho, Alfi Syahri, and Lia for guidance, support and deep insight into the study.

GLOSSARY OF TERMS

^ǇŵďŽů ĞĮŶŝƟŽŶ hŶŝƚ

Ap Area of Plunger Inch²

Ar Area of Rod Inch²

At Area of Tubing Inch²

DFL Dynamic Fluid Level �

�r �las�c Rod Inch

�t �las�c of Tubing Inch

HP Horse Power HP

MPRL Minimum Polished Road Load lb

SL Stroke Length Inch

SPM Stroke Per Minute

PD Pump Displacement Bpd

PI Produc�vity Inde� Bpd�psi

Pr Reservior Pressure Psi

Ps Sta�c Pressure Psi

PSD Pump Se�ng Depth Ft

PwF Flowing Well Pressure Psi

SFL Sta�c Fluid Level Ft

SGo Spesiﬁc Gravity of Oil ‐

SGw Spesiﬁc Gravity of Water ‐

SGf Spesiﬁc Gravity of Fluid ‐

Wr Weight of Rod Lb

HP Horse Power HP

Wr Weight of Rod Lb

HP Horse Power HP

Wr Weight of Rod Lb

HP Horse Power HP

Wr Weight of Rod Lb

Wf Weight of Fluid Lb

HP Horse Power HP

Wr Weight of Rod Lb

HP Horse Power HP

Wr Weight of Rod Lb

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Nodal Analysis”. Houston,

Pertamina.2021. “Production History Sumur.

Takacs,Gabor.2015.”Sucker Rod Pumping Hand- book, Production Engineering Fundamental and Long Stroke Rod”.University of Miskolc:

Hungary.

Tobing,Edward.2007.Analisis Produktivitas Sumur Diperforasi Menggunakan Persamaan Kurva IPR Aliran Dua Fase.Lembaran Publikasi Minyak dan Gas Bumi. Vol 41 No 2.

Tobing.Edward.2013. Influence of Flow Rate and Time on Skin Factor in Solution Gas Drive Oil Reservoir. Lembaran Publikasi Minyak dan Gas Bumi.Vol 47 No 3.

Tutta. 2013.”Hydraulic Pumping Unit Operational Manual”