Testing Equipment for API RP 13B-1

Testing Equipment for API RP 13B-1

Testing Equipment for API RP 13B-1

The American Petroleum Institute (API) Recommended Practice 13B-1 (RP 13B-1) establishes recommended practices for field testing water-based drilling fluids. OFITE offers equipment for testing water-based drilling fluids based on this document.


For testing drilling fluid density, OFITE offers the 4 Scale Metal Mud Balance (#115-00). It measures density in lbs/gal, specific gravity, lbs/ft3, and PSI/1000 ft and meets all of the specifications in API RP 13B-1 Section 4.  The rugged, stainless steel design is perfect for field or laboratory use.

Section 5 of the document details the procedure for measuring the density of a drilling fluid under pressure.  The Pressurized Fluid Density Scale (#100-70) works on the same principle as the standard mud balance, but it incorporates a plunger for pressurizing the fluid sample.

Viscosity and Gel Strength

The Marsh Funnel Viscometer (#110-10) measures the funnel viscosity of a drilling fluid as described in section 6.2.

Section 6.3 describes the procedure for using a direct-indicating viscometer.  Three options are available:

  • Hand Crank Rheometer (#132-00): This light-weight viscometer is powered by a hand crank.  It does not require electricity, which makes it perfect for portable kits.  It has two speeds (300 and 600 RPM) and a knob for measuring gel strength.
  • Model 800 Viscometer (#130-10-C): This viscometer is powered by DC voltage, which makes it ideal for international use.  The included power supply works with available power in any country.
  • Model 900 Viscometer (#130-76-C): The Model 900 is a full-featured viscometer that can operate with a computer or as a standalone instrument.  The variable speed motor ranges from .01 to 1000 RPM.  With the ORCADA® software, the user can build and store custom, automated tests.


Section 7 specifies both low and high pressure filtration.  

Low Temperature / Low Pressure

We offer several solutions for low temperature, low pressure testing.  The basic model is the Benchmount API Filter Press (#140-20).  It includes a pressure cell, benchmount frame, gaskets, and a screen.  Other models include pressure assemblies, like the #140-30, which features a built-in CO2 pressure regulator. All models meet the specifications listed in section 7.2.

High Temperature / High Pressure

 We also offer several options for high temperature, high pressure (HTHP) filtration testing.  Two sizes (175 mL and 500 mL) and two pressure media (CO2 and N2) are available.

Water, Oil, and Solids Content

Retort analysis is listed in Section 8.  OFITE offers four options:

Sand Content

Section 9 covers sand content.  The Sand Content Kit (#167-00-C) contains everything necessary to perform this test.

Methylene Blue Capacity

Section 10 covers methylene blue capacity.  The Methylene Blue Test Kit (#168-00) contains filter paper, glassware, a hot plate, and reagents, all packaged in a durable stainless steel case.


As discussed in Section 11, measuring the pH of drilling fluid is fo critical importance.  OFITE offers a wide range or equipment for pH Analysis, include laboratory meters, portable meters, and pH paper.

Chloride, Alkalinity, Hardness, and Lime Content

For determining the chloride content, alkalinity, hardness, and lime content of a fluid sample as discussed in Sections 12, 13, and 14, OFITE offers several filtrate analysis kits

Calcium and Magnesium

In Annex A, Sections A1, A2, and A3, the API details the procedure for determining the Calcium and Magnesium content of a drilling fluid sample. The Calcium and Magnesium Kit provides all the necessary equipment in a single kit.

Sulfide and Carbonate

In Annex A, Sections A4 and A5, is the procedure for using a Garrett Gas Train (#151-00) to determine the sulfide and carbonate concentration of a drilling fluid.


Sections A7 and A8 deal with Potassium concentration.  We offer three options:

Shear Strength

Annex B recommends using a shearometer tube to measure the shear strength of drilling fluid.  OFITE offers a Shearometer Kit (#166-08), which includes two tubes and a cup with a graduated scale and also a standalone Shearometer Tube with Weight Support (#166-10).


 Annex C deals with measuring resistivity.  OFITE provides a Digital Resistivity Meter (#130-87) and an Analog Resistivity Meter (#130-85).

Removal of Air or Gas Prior to Testing

For removing air or gas from a drilling fluid per Annex D, see the Mud Deaerator (#110-00).

Drill Pipe Corrosion Rings and Coupons

OFITE offers a complete line of Corrosion Rings and Coupons as specified in Annex E.

Permeability Plugging Apparatus

The Permeability Plugging Apparatus (sometimes called the Permeability Plugging Tester) is described in Annex I (#171-90) and Annex J (#171-193).