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What Is “About” About?

02-1496
August 06, 2003
Sweet, Mark D.

Decision icon Decision

Last Month at the Federal Circuit - September 2003

Judges: Mayer (author), Dyk, and Prost

In BJ Services Company v. Halliburton Energy Services, Inc., No. 02-1496 (Fed. Cir. Aug. 6, 2003), the Federal Circuit affirmed a district court’s decision holding a claim of U.S. Patent No. 6,017,855 (“the ’855 patent”) valid and infringed.

BJ Services Company (“BJ Services”) is the owner of the ‘855 patent, which is directed to a method of fracturing subterranean formations to stimulate oil and gas wells. The sole claim at issue is directed to forming a base fluid by blending together an aqueous fluid and carboxymethyl guar, which has a C* value of about 0.06 percent by weight, adding a crosslinking agent to the base fluid to form a gel, and injecting the gel into at least a portion of a subterranean formation at high pressure to form fractures within the formation.

BJ Services brought suit against Halliburton Energy Services, Inc. (“Halliburton”), claiming that Halliburton infringed the sole claim at issue in the ’855 patent. Halliburton argued that the ‘855 patent was invalid because the claim was indefinite, the specification was not enabling to one of skill in the art, the claim was anticipated, and the ‘855 patent did not name the proper inventors. A jury found the claim in the ‘855 patent valid and infringed, and awarded damages to BJ Services.

On appeal, the Federal Circuit held that a reasonable jury could find that the claim in the ‘855 patent was not invalid for lack of enablement. In response to the argument that the ’855 patent does not enable the method and conditions used to measure C*, the Federal Circuit concluded that while the patent was silent about the measurement conditions and while the C* value may vary depending upon the chosen conditions, evidence was presented at trial in the form of the testimony of the inventors of the ‘855 patent, testimony of a rheology expert, and excerpts from a textbook to support the jury’s conclusion that one of skill in the art would have known how to measure C*.

The Federal Circuit also ruled that a reasonable jury could find that the asserted claim was not invalid for indefiniteness based on the term “about 0.06.” The Court relied on experimental results presented by BJ Services that averaged slightly below 0.06 to support the finding of the jury that the term “about” was intended to encompass a range of experimental error.

The Federal Circuit additionally held that the claim of the ‘855 patent was not anticipated by U.S. Patent No. 5,697,444 to Moorhouse(“Moorhouse”). Moorhouse disclosed a fracturing fluid comprising one or more polymers, preferably carboxymethyl guar, but did not disclose the C* value, which was later measured as 0.077. In the district court, the jury was instructed to give “about 0.06” its plain and ordinary meaning. Because the term “about” was used to encompass experimental error and the jury had before it the typical experimental range, the Federal Circuit held that substantial evidence supports the jury’s finding that Moorhouse’s C* value of 0.077 does not anticipate the C* value of about 0.06 recited in the claim of the ’855 patent.

Finally, the Federal Circuit held that evidence at trial supported the jury’s finding that the ’855 patent was not invalid for failing to name the proper inventors. The claim at issue was directed to a method of fracturing a subterranean formation using a polymer with a certain C* value. The Federal Circuit ruled that the claim was not to the polymer itself but rather to a method that incorporates that polymer. The evidence at trial indicated that the inventor of the polymer had no knowledge of the method, how the polymer would be used, or the C* value.