With crude trading near a 26-month high, oil stocks are in demand.Big hitters such as BP, BG and Cairn Energy are posting gains, but it is not all cheer in the sector. Desire Petroleum's shares have collapsed after it said it has plugged and abandoned the 14/15-2 Rachel North well.Alternative energy stocks are also going well, with filtration and environmental technologies supplier Porvair among the risers after saying that its full year figures will be better than expected due to strong fourth quarter trading.Tesco is helping to drag the food retail sector lower. The supermarket giant issues a trading update tomorrow.Top performing sectors so far todayOil & Gas Producers 7,925.47 +2.00%Alternative Energy 3,581.76 +1.89%Personal Goods 19,225.93 +1.64%Fixed Line Telecommunications 2,277.96 +1.55%Construction & Materials 3,708.88 +1.43%Bottom performing sectors so far todayFood & Drug Retailers 4,803.16 -1.28%Industrial Metals & Mining 7,476.72 -1.10%Forestry & Paper 5,355.52 -0.86%Media 3,963.62 -0.65%Real Estate Investment Trusts 1,957.64 -0.65%