Optimizing Artificial Lift System Placement in Horizontal Wells

Transcription

1 RM26 Optimizing Artificial Lift System Placement in Horizontal Wells Author: Timothy Gorham Business Unit: San Joaquin Valley Business Unit

2 Outline History and use of horizontal wells in the San Joaquin Valley (SJVBU) Optimizing artificial lift in existing horizontal wells Insight to planning new horizontal wells Summary 2

3 History of horizontal wells in SJVBU

4 SJVBU Major Fields COALINGA Coalinga: Heavy Oil, Steamflood SJVBU SAN ARDO Lost Hills: Light Oil/Gas, Waterflood San Ardo: Heavy Oil, Steamflood LOST HILLS Kern River: Heavy Oil, Steamflood Cymric: Heavy Oil, Cyclic/Steamflood NORTH BELRIDGE SOUTH BELRIDGE CYMRIC SHAFTER BAKERSFIELD KERN FRONT MOUNT POSO KERN RIVER CALIFORNIA NEVADA Elk Hills: Light Oil/Gas, Non-Operated MCKITTRICK MIDWAY SUNSET ELK HILLS BUENA VISTA TAFT EDISON PACIFIC OCEAN N 0 5 MILES SCALE SELECTED OIL FIELD Midway Sunset: Heavy Oil, Steamflood MARICOPA 4

5 Production Impact of Horizontal Wells 18,000 12,000 Kern River 15,000 Cymric/Mckittrick MWSS Coalinga/San Ardo BOPD 9,000 6,000 3,000 - Jan-94 Jan-96 Jan-98 Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 5

6 Ideal SJV (heavy oil/gravity drainage) Horizontal Completion 4-1/2 to 6-5/8 slotted liner +1,000 ft lateral section drill slightly up dip (2-4 ) so oil drains back to sump 7 to 9-5/8 surface casing TVD 600 to 2,000 Plan for maximum TVD be in surface to create sump for artificial lift 6

7 Real World Horizontal Completion High Dogleg Severity (DLS) what is the max DLS we can handle? Where s the best location to place the pump? (TVD, Inclination, Tangent Section, Desat Elev) Max TVD below liner top. Will this significantly reduce ultimate recovery? 7

8 Problem/Opportunity Ops and PE s don t have software to visualize H wells No way to know if horizontal wells are optimized We can t count on Ops long term experience anymore We can look at one well at a time manually (usually only problem wells and we ignore OK wells) 8

9 Surveillance tool to Optimize i Horizontal wells

10 Part 1 (Field Surveillance Tool) Flag Control Wells we need to review the pump depth 10

11 Part 2 (Individual Well Visualization TVD and Elevation) 11

12 So what s the impact so far? +400 BOPD Day_Oil (G Gauge Oil acc counting for down time) Day Oil Base Incremental 0 Jan-08 Mar-08 May-08 Jul-08 Sep-08 Nov-08 Jan-09 Mar

13 Identifying Undrainable Reserves Pump is already near optimum depth, but still 100 above bottom of well 13

14 Identifying undrainable oil helps in Peer Heat Reviews and drainage reviews 8Z H-130T Measured Depth (ft) 600 1,100 1,600 2,100 2,600 3, Well Path Casing (ID = 6.366'') Liner (ID = 4.'') Current Pump Location 650 Max TVD 85 Deg Inclination 15 DLS Drift DLS for a 3 3/4'' by 26' pump Tr rue Vertical De epth (ft) Dog gleg Severity (D Deg/100')

15 We need to also factor in Dogleg Severity in pump placement Dogleg Severity (DLS) is measurement of well path curvature. DLS/100 ft Current rule of thumb is stay below 15 /100 Pump OD and Length Casing ID An equation for DLS Drift (thanks to Lilianna Vera) DLS Drift ( ID csg Lpump 2 OD Pump ) 4( ID csg OD Pump ) 15

16 Drift Model confirmed by field data 1,000 5Z H-110T Measured Depth (ft) 700 1,200 1,700 2,200 2,700 3, Well Path Casing (ID = 8.921'') Liner (ID = 5.921'') 1,020 Current Pump Location Max TVD Location Deg Inclination True Vertical Dep pth (ft) 1,060 1,080 We re exceeding pump Dogleg Severity (D Deg/100') 1,100 1, ,

17 5Z H-110T notes tight

18 ID wells that we ll have to adapt as they mature rue Vertical De epth (ft) T WIB H53T Measured Depth (ft) ,100 1,300 1,500 1,700 1,900 2,100 2,300 2, Well Path Casing (ID = 7.636'') Liner (ID = 4.892'') Current Pump Location Max TVD Location Deg Inclination DLS Drift DLS for a 3 3/4'' by 33' pump Dog gleg Severity (D Deg/100')

19 With a smaller/shorter pump at later date Tr rue Vertical De epth (ft) Measured Depth (ft) ,100 1,300 1,500 1,700 1,900 2,100 2,300 2, Well Path Casing (ID = 7.636'') Liner (ID = 4.892'') Current Pump Location Max TVD Location Deg Inclination DLS Drift DLS for a 2 3/4'' by 26' pump Dog gleg Severity (D Deg/100') 900 By running a smaller/shorter pump we can capture +50 of oil

20 Planning new horizontal wells (How crooked is too crooked?)

21 Do we need a pump Tangent Section? Drift Dogleg Severity ( /100') for typical pump and casing size combinations Casing Size Production 5-1/2'' 51/2 7'' 8-5/8'' 85/8 9-5/8'' 95/8 Pump Size Rate 17# 23# 32# 36# 2" x 22' < /4" 2-1/4" x 24' /4" x 24' /4" x 26' /4" x 26' /4" x 36' +1,

22 Are rod and tubing (R&T) failures a function of Max DLS? Most of the bad wells are in Cymric High DLS, yet little R&T Failure 22

23 R&T failures appear to be more function of pump size 23

24 Optimizing Artificial Lift System Placement in Horizontal Wells (Existing Horizontal wells) Lessons Learned: 1. Artificial lift placement is a critical for current production rate and ultimate recovery in gravity drainage reservoirs 2. Tangent drift equation determines if we need to set pump in a tangent section as function of expected flow rate and casing size Best Practices: 1. Use measured depth instead of departure for operational plots Challenges: 1. MD vs TVD (Lease reviews and day to day Ops) 2. MD vs Elevation (Drainage reviews and Peer Heat Reviews) 1. We still don t have an Chevron official tool 1. Working on adding info the LOWIS 2. SJVBU I-field team aware of data 24

25 Optimizing Artificial Lift System Placement in Horizontal Wells (Planning New Horizontal wells) Lessons Learned: 1. If we re drilling into an area with a chance sump will be in liner, don t use 4-1/2 liner 2. Rod and tubing wear are more related to pump size than absolute dogleg severity Best Practices: 1. For higher volume targets (+1000 BPD), we should be more careful in drilling the build section to avoid doglegs (>10) 2. For lower volume targets (<500 BPD), we could operate with higher DLS severity and no tangent sections Challenges: 1. Drill faster and reduce drilling costs 2. Review opportunities previously deferred due to complex 1. The tangent t model only tells when we start t to bend the pumps, but it doesn t calculate the operability limit 25