ExxonMobil Corp. in July quietly purchased more acreage in the Haynesville/Bossier Shale, a company executive disclosed Thursday.

David Rosenthal, vice president of investor relations, discussed the company’s performance in 3Q2010 during a conference call with energy analysts. He said ExxonMobil had purchased Denver-based Ellora Energy in July. As it has done in the past, the $695 million all-cash Ellora acquisition was quietly completed.

Ellora’s year-end 2009 proved reserves totaled 61 Bcfe, which were weighted 99% to gas and 48% proved developed. At the end of June production was 13.2 MMcfe/d from about 46,000 net acres in the Haynesville/Bossier plays. In addition, Ellora owned a 100-mile pipeline system in the area.

Rosenthal downplayed the acquisition in his remarks. The purchase so far has had “a de minimus impact on both production and cost…But we are looking forward to what it will bring to us in the future.”

ExxonMobil became the largest onshore gas producer in the country when it completed its purchase in June of shale king XTO Energy Corp. (see Daily GPI, June 28). With the transaction, ExxonMobil also gained more operating gas rigs. However, the producer’s gas rig count remains close to what it was prior to the transaction, said Rosenthal.

ConocoPhillips on Wednesday announced that it had shut in 180 MMcfe/d of gas in North America (see Shale Daily, Oct. 28). ExxonMobil has no such plans.

“Looking at that business,” Rosenthal said of U.S. operations, “we have not shut in any gas wells. Activity continues on pace to what we’ve been running…” There are no plans for shut-ins, he said.

“We’ve got about 68 to 70 rigs running today, and that’s consistent with where we were in the past,” he said. “As we look out to the end of the year, essentially it will be in the plus or minus 70 [rig count] category. There are no major changes up or down.”

XTO, which has since become a Fort Worth, TX-based subsidiary of ExxonMobil, at the time of the merger had a resource base of 45 Tcf of gas, including shale gas, tight gas, coalbed methane and shale oil in nearly every identified shale basin in the United States.