An increase in rigs being put back to work in U.S. shale fields is largely being driven by smaller oil companies drilling less-complex wells that don’t need costly, high-tech services offered by industry leaders such as Halliburton Co. The upshot? Halliburton and larger rival Schlumberger NV’s gains from the rise in rig count is expected to be limited in the short term as smaller oilfield services companies such as RPC Inc swoop in to fill the gap. Large oilfield services providers are typically hired by big oil companies that want to drill faster and frack wells intensively with more fluids and sand and multiple frack stages to boost production. “We saw a trend of less service-intensive wells, which is not activity typically worth chasing […]