PIPE-LAX OB

Oil-based spotting fluid

Schlumberger Oilfield Services

PIPE-LAX OB fluid is a spotting fluid designed to free stuck drillstrings when using invert-emulsion drilling fluids. It frees the drillstring by penetrating and cracking the filtercake to free differentially stuck pipe.

Typical Physical Properties
Physical appearance Liquid
Odor Slight
Solubility in water Dispersible
Specific gravity 0.98–1.0
Flash point 220 degF [104 degC]

Applications

Success in freeing differentially stuck pipe is greatest when the spotting fluid is applied as soon as possible after the pipe becomes stuck. A fluid that can be mixed and spotted quickly often frees the drillstring before fishing operations are required. Because PIPE-LAX OB fluid is a singly-packaged, liquid blend made for fast mixing it is ideal for spotting situations.

Advantages

  • Effective at cracking the filtercake in nonaqueous fluid systems
  • Temperature stable to >350 degF [>177 degC]
  • Compatible with invert fluids; it can be incorporated to the system (1–5% by volume final concentration) without adversely affecting mud properties. Pilot testing to confirm compatibility is recommended.
  • Can be easily weighted with M-I BAR barite, M-I WATE barite, or FER-OX agent.

Mixing formulation (per final barrel or per final cubic meter)

Density, ppg [sg] PIPE-LAX OB Fluid, bbl [m3] M-I BAR Barite, lbm [kg] PIPE-LAX OB Fluid, bbl [m3] FER-OX Agent, lbm [kg] PIPE-LAX OB Fluid, bbl [m3] M-I WATE Barite, lbm [kg]
9.0 [1.08] 0.975 [0.155] 37 [16.8] 0.980 [0.156] 35 [15.9] 0.974 [0.155] 37 [16.8]
10.0 [1.20] 0.938 [0.15] 92 [41.7] 0.950 [0.151] 87 [39.5] 0.936 [0.149] 93 [42.2]
11.0 [1.32] 0.900 [0.143] 147 [66.7] 0.920 [0.146] 140 [63.5] 0.897 [0.143] 148 [67.1]
12.0 [1.44] 0.863 [0.137] 202 [91.6] 0.890 [0.141] 192 [87.1] 0.858 [0.136] 204 [92.5]
13.0 [1.56] 0.825 [0.131] 257 [116.6] 0.860 [0.137] 245 [111.1] 0.819 [0.13] 259 [117.5]
14.0 [1.68] 0.788 [0.125] 312 [141.5] 0.830 [0.132] 297 [134.7] 0.781 [0.124] 315 [142.9]
15.0 [1.80] 0.750 [0.12] 367 [166.5] 0.800 [0.127] 350 [158.8] 0.742 [0.118] 370 [167.8]
16.0 [1.92] 0.713 [0.113] 423 [191.9] 0.770 [0.122] 402 [182.3] 0.703 [0.112] 426 [193.2]

Mixing procedure

  1. Calculate the volume of spotting fluid required and add at least 10% to compensate for any washout. In addition, include 25 bbl [3.97 m3] to remain in the drillstring.
  2. In a clean, dry tank, mix the required amount of PIPE-LAX OB fluid determined from the mixing formulation chart.
  3. If the slurry is to be weighted, add the correct amount of barite or weighting materials until thoroughly blended.
  4. Displace the slurry to the zone where the differential sticking is suspected. Leave 25 bbl [3.97 m3] inside the pipe to displace at an hourly rate into the openhole.
  5. Work the pipe while the spotting fluid is soaking. Pump 0.5–1.0 bbl [0.08–0.16 m3] every half hour to assure fresh soak solution is being displaced into the openhole.
  6. Allow at least 24 h for the PIPE-LAX OB fluid to free stuck pipe. Unweighted spotting fluids are generally effective in a shorter period of time.

When using PIPE-LAX OB fluid in deviated wells with angles greater than 35°, the spotting fluid should be weighted 0.5 ppg [0.06 sg] heavier than the original fluid in the well to encourage the spotting fluid to migrate to the lower side of the hole.

Limitations

  • Addition of this product to a synthetic fluid may cause the system to fail bioassay testing

Toxicity and handling

Bioassay information is available upon request. Handle as an industrial chemical, wearing protective equipment and observing the precautions described in the safety data sheet.

Packaging and storage

PIPE-LAX OB fluid is packaged in 55-galUS [208-L] drums. Store in a dry, well-ventilated area. Keep container closed. Keep away from heat, sparks and flames. Store away from incompatibles. Follow safe warehousing practices regarding palletizing, banding, shrink-wrapping, and stacking.