Feasibility of Using Laser Bit Beside of Common Bits to Drilling Slim Holes

The capability level of rotary as well as first generation drilling operation could not be matched for deeply drilling programs. To reach that deep, the increasing in drill string length could also cause an additional constraint on hydraulic performance. The operation of slim hole drilling has significant potential to reduce well costs. This cost might be savings are especially important with increased demand for reduced capital finance under current economic conditions in the Iranian oil and gas industry. This savings achievement could be caused by use of smaller drilling rigs, work over rigs, reduced casing size, reducing requirement for drilling consumables and other costs associated with hole size. Otherwise, using laser irradiation for drilling operation can save cost little more higher look like do not using casing and perforation in reservoir layer for slim hole which are drilled by high power laser systems. As the matter of fact, Cost savings achieved from slim hole drilling could be offset by inability to effectively transmit the weight to the bit, increased mechanical failures of drill pipes and tools and reduced the well bore instability effects in particular, in drilling operation at greater depths This paper investigates the effects of borehole parameters during laser drilling operations in the case of slim hole.