Abstract: A friction reducer includes a polysaccharide-graft-water-soluble polymer is provided. A polysaccharide in an amount of from about 0.1 to 50% by weight (wt. %) may make up the polysaccharide-graft-water-soluble polymer. A wellbore treatment fluid is provided that includes an aqueous base fluid and the friction reducer in an amount up to about 10% of the wellbore treatment fluid. A method of using a wellbore treatment fluid includes the step of introducing the wellbore treatment fluid as previously provided into a wellbore.

Abstract: A method of measuring a formation parameter in the process of drilling a well penetrating the rock formation is disclosed. A section of the well is provided with a drill string comprising a drilling bit at its distal end; a first fluid is circulated through the drilling bit and invades the rock formation; a formation evaluation tool mounted onto the drill string is used to measure the formation parameter; the formation parameter is used to select the time at which a second fluid is circulated through the drilling bit; such that the second fluid alters the response of the rock formation to the formation evaluation tool; the second fluid is circulated through the drilling bit to start invading the formation; and the formation evaluation tool is used to repeat the measure of the formation parameter while circulating the second fluid.

Abstract: Methods and systems are described for using pulsed neutron ?-ray spectroscopy to measure formation water salinity from within a bore-hole. Through generating a cross-plot of database values of ratios of spectroscopically determined yields of hydrogen (H) and chlorine (Cl) from two detectors, deriving apparent salinities therefrom, formation and borehole water salinities can be determined.