Optimization of Multiple Bit Runs Based on ROP Models and Cost Equation for One of the Persian Gulf Carbonate Reservoirs

According to the conventional drilling cost equation, the key to minimize the drilling cost would be the increase of rate of penetration (ROP). Several ROP models have been developed and modified based on the concept of unconfined compressive strength (UCS). These models can predict the rate of penetration of different bit types in an oil or gas field with a reasonable degree of accuracy.The ROP model derived by Warren and modified by Hareland relates the rate of penetration to operating conditions, rock strength and bit parameters. Also, the effects of hole cleaning and bit wear on rate of penetration have been included in this model. This model is capable of accurately simulating the drilling of a well and producing a reliable rate of penetration at any specific depth.In this paper, the information from one of the Middle East carbonate fields was utilized to optimize the drilling costs for upcoming wells in this field. This has been done by creating an Apparent Rock Strength Log (ARSL) along the wellbore and developing the Modified Warren’s Model with new constants for this field. The concept of a learning curve has been used by conducting a number of simulations to obtain the optimum bit hydraulics, best combination of drilling parameters (WOB and RPM) and the most effective bit pull depth.The approach used in this study can be used in pre-planning and post analysis to minimize the cost of drilling operations and reduce drilling costs on any development wells where wells were previously drilled.

کلیدواژه ها:

Drilling Optimization ، Rate of Penetration Model ، Apparent Rock Strength Log ، Drilling Cost Equation ، Drilling Simulator ، Bit Run Depth