Unitalen Client Schlumberger Maintained Two Basic Patents Successfully

September 11, 2020


The patentee M-I Co., Ltd. belongs to Schlumberger, the world's largest multinational oilfield technology service group. Schlumberger and its subsidiaries and affiliates have a large number of basic patents in various fields of oilfield technology.

In the second half of 2019, M-I Co., Ltd. initiated a 337 investigation against a Hebei machinery manufacturer. through the U.S. International Trade Commission (USITC) and filed multiple patent infringement lawsuits in the Beijing Intellectual Property Court of China.

Against the Chinese invention patents on frames and screen meshes owned by MI Co., Ltd. involved in the above-mentioned patent infringement litigation and its family invention patents, the Hebei machinery manufacturer (hereinafter referred to as “the requester”), submitted to the Patent Office of China IP Administration (CNIPA) at the end of 2019 and early 2020, respectively the invalidation requests. In the two requests, the requester listed a large amount of evidence in attempt to prove that the patents in question are not inventive by means of a combination of technical features.

CNIPA Ruling:

The legal team of Unitalen, entrusted by the patentee M-I Co., Ltd., explained in details the technical solutions of the patents involved and prior arts concerned to the CNIPA, with in-depth reasoning and analyses presented following the three-step evaluation criteria of the examination, and successfully had the CNIPA rule to maintain effective all the rights of the two patents involved.


The focus of the above-mentioned two invalidations is how to determine the technical problem solved by the distinguishing technical features, and on top this, how to determine whether the prior art has inspired the invention.

For example, in the invalidation request involved, both the requester and the patentee agree that there is at least one difference between Claim 1 of the patent involved and Evidence 1, Evidence 2 or Evidence 6 exits, i.e. the edge areas of the molded plastic frame are reinforced from the inside by metal box-shaped cross-section members connected at their four corners and defining peripheral reinforcements, and the ends of the metal wires are fixed to the metal box Sectional parts. Regarding this distinguishing technical feature, the requester believes that its role is to consolidate the strength of the entire screen frame, and Evidence 3 to 7 all disclose the use of metal box-shaped cross-section square tube profiles as the peripheral area to serve this. Therefore, inevitably, they provide technical enlightenment, so that Claim 1 is not inventive subject to the combination. But in fact, taking into account of the underlying technology of the patent involved, it’s found that the technical problems that the inventor faced during invention were excessive vibration of the screen, fluid bypass, seal damage, and excessive splashing. Through inventive work, the inventor discovered that increasing the strength of the screen frame can avoid the excessive shaking and other problems. Therefore, with the above-mentioned distinguishing technical features, the technical problem actually solved by the patent involved should be to improve the strength of the screen frame and avoid excessive shaking during use. As for the solution of this technical problem, other prior arts have not given any enlightenment, and even the technical idea is completely different. Thereby the collegiate panel maintained the validity of the patent right in question.

Similar for the other patent, the collegiate panel ruled to maintain the validity of the patent right because the requester has misunderstood the technical problem solved by the distinguishing technical features, none of the reasons for the request could be established.

Further on how to identify the technical problems solved by distinguishing technical features, which is the core of this case.

In the amendment to the "Patent Examination Guidelines" issued in the CNIPA No. 328 Announcement, the second step of the three-step method of determining inventiveness has clearly stipulated that "the technical problem actually solved by the invention needs to be determined according to the technical effect that the distinguishing feature can achieve in the claimed invention ". The requester in this case mistook that the invention involved can be obtained "easily" combining the features of prior art. With the target invention as the benchmark and beacon, it is simple and easy to find technical features from prior art to compare to; but, how to determine the benchmark and beacon in absence of the target invention? During invention, a technical person is faced with a huge amount of prior art. If there is no clear technical enlightenment, as an uncreative "person", he will not know how to use the prior art to solve the actual problem, even though the solution itself may not be difficult and complicated. Therefore, inventions that seem obvious on the surface may actually be inventive.