A high-ranking delegation of petroleum experts from the People's Republic of China is touring U.S. energy complexes, and many experts hope the visit will lead to more multimillion-dollar oil equipment sales to the Chinese.

The 16 petroleum officials are seeing almost every aspect of the oil production industry, from the seismic equipment that charts geologic structures to the drilling bits and rigs used to tap oil reservoirs to the refineries that transform crude into usable products.

But beyond any commercial sales, officials see the trip as one more opportunity to improve relations between the two nations -- the thing that many people feel is necessary if still larger equipment sales are to become a reality.

"It is extremely significant in causing developments in international relations," says J. Ray Pace, president of Baker Trading Co. here, which specializes in sale of petroleum and mining equipment to certain nations, including China.

"Right now, most of the push in improving relations is coming from the business community. We're having to do business with them over great obstacles," namely the lack of diplomatic relations.

The result is that credit cannot be extended to the Chinese and purchases must be in cash. In addition, certain equipment and technology with military implications cannot be exported to China. And because of the lack of formal relations, the oil equipment industry, which employs thousands here, has become a corps of citizen diplomats in entertaining and assisting the Chinese visitors.

The chinese have, since 1973, purchased at least $150 million in petroleum exploration, drilling and production equipment from the United States; $100 million in petrochemical processes, and $200 million in construction of eight ammonia plants, according to the Commerce Department.

The Department of Energy, which is otherwise none too popular among firms doing business in what Texans like to call the oil patch, has attached special political meaning to the trip --it is the first delegation from China to visit the United States at the invitation and expense of the federal government. Others see the trip, however, as comparable to that of a June, 1977, delegation whose trip here led to the sale of two fixed offshore oil platforms by the National Supply Co., a division of Armco Steel.

In terms of developing trade potential, petroleum equipment sales rank second only to agriculture, says Young. The Chinese have also bought petroleum equipment elsewhere in the world and will spend 12 days in Japan after they leave the U.S. Jan. 30.

The search for the latest in high technology is seen not as a Chinese admission of failure but as an effort to add to the already great strides Peking has made in developing oil resources. China's production of crude oil is estimated at 83.6 million tons in 1976 compared to one-sixth of that in 1966.

The nation is able to export some quantities of oil, mostly to Japan, and the United States has an interest in seeing that figure rise as part of worldwide efforts to increase energy supplies. Peking has announced an ambitious goal of developing 10 new oilfields each rivaling China's largest current reserve at Taching.

The current trip, then, "is an indication that policymakers have a real interest in the U.S. petroleum equipment industry as a source of technology, which will apparently be taken into account in augmenting the development of their own resources," said Pace.

"China is reaching out to acquire know-how," says Young. "They're ready to buy capital equipment."

Whether they will may take months to know, as lengthening negotiations proceed in Peking within the government and between the Chinese and foreign suppliers. Weighing into it all will be the trainign films, slides, production facilities and manufacturing techniques the Chinese have absorbed in their tours through American industries and in government seminars.They have been asking technical questions and taking notes in palm-sized red or blue notebooks.

They have been treated to dinner at the Houston home of George Bush, former CIA director and former head of the U.S. delegation to Peking. The delegation has been staying at the plush, new Galleria Plaza Hotel and treated its American hosts to a Chinese dinner here.

Bush described the dinner at his home as "relaxed" and added: "They are indeed going to step up their goal of self-reliance in the not too distant future. The only question is how much (business) they're willing to do with the United States."

Bush said that while two of the delegation's members hold the rank of vice minister, the group is more technical than political and thus not likely to discuss issues such as U.S. relations with Taiwan and settlement of property claims growing out of the Communist takeover in 1949.