WW 1(Ottoman fronts)

The Ottoman empire was somewhat involved in the war. There was a fairly significant war between the Ottomans and Russia around the Caucasus, plus the fighting with the British and ANZAC at Gallipolli (where the Turks did quite well actually). On top of this, there was the war on the Middle-Eastern front, in Palestine, where the Arab insurrection made famous by T.E. Lawrence was initally just a sideshow to the main war fought by the British and the Turks.

As for the oil fields, the Mosul fields were already in use by 1914, as opposed to the Iranian and Saudi ones which were in use in the 1930s. In fact, there are some who believe that oil was one of the major factors in starting the war. The main issue in the Middle East at the start of the war was the proposed Berlin-Baghdad railway, which was to give Germany access to the Mosul oilfields. While oil was not crucial yet for fighting a land war, it had become crucial for domination of the seas ever since the appearance of the Dreadnought-class battleships. Germany needed the oil if it was to challenge Britain's naval domination (and it certainly attempted to do so). With the railway in place, Germany would have had the oil fields of Mosul; coupled with Germany quickly catching up with Britain in dreadnought numbers, this could have conceivably led to a very serious challenge to Britains' naval domination by 1920. It was fortunate for the British that the war started when it did, otherwise they conceivably could have lost their status as a major world power, to Germany.

Cyprus was assigned to the British specifically because of Britain's role supporting the Ottoman Empire against the Russians. Egypt was brought under British influence (it nominally remained part of the Ottoman Empire while it lasted) mostly to secure the Suez Canal and the route to India, which was also why the British had been extending their 'protection' to the Gulf sheikhdoms for some time. But as of 1913, the position in the Gulf was agreed between the two Empires, and e.g., the Sabah rulers of Kuwait were recognised by both parties not as independent but as Ottoman sub-governors ('qaimmaqams').