london jan 31 reuters  the structure of the global oil market was increasingly backwardated on monday signalling the likelihood of reductions to offers of west african crude which remains at highs last seen in mid2020  the sixmonth spread between brent for march delivery versus september delivery was 675 on friday the steepest since 2013  the backwardation market structure is reached when nearterm prices are higher than those of laterdated contracts encouraging prompt oil sales and discouraging longhaul purchases such as those from west africa to its main markets  chinese buying had helped to prop up offers in the first couple weeks of the trading cycle for marchloading crude but is likely to pause this week because of lunar new year celebrations  angolan girassol and nigerian forcados were both last offered at dated brent plus 3 a barrel their highest since spring 2020  us crude production rose 2 month on month in november to 11753 million barrels per day according to a monthly report on monday from the us energy information administration  opecs oil output in january has again undershot the rise planned under a deal with allies a reuters survey found on monday highlighting some producers struggle to pump more crude as prices trade at a sevenyear high