Comparison of the costs of implementing methods to deal with the lack of wellbore stability

The stability of the oil wells can lead to major problems in the oil and gas drilling industry mainly due to high restoration expenses and the risk of endangering operation crew of rig. In one hand, Similar to any operational process cost effective drilling in the oil and gas industry is one of the main goals of each drilling mission. On the other hand, due to high-pressure and low-pressure sequence of layers in the field study, stability of the oil wells and their operational time is crucial. Therefore, in the present study the costs of cementing and drilling mud which are performed to improve the stability of the wells are compared. Therefore, drilling operation data acquired from one of the wells in the oil fields of Iran that include the cost of oil-based additives which are added to the weight of 102 PCF mud and cement costs have been utilized. These data are used to compare the cost of strengthening operations to evaluate the cost-effectiveness of each method. The depths of the measurements were collected from five intervals which contains 9 FIT test and 7 cementing, that uses the private cost functions modeling. In addition to the cost, the drilling time is also influential in that the cementing work is time-consuming if not done carefully. But if mud loss occurs during cementing work, it may result in extensive time and money loss. The results of this study indicate that less than 4 times the performance of cement in cement injection is efficient and economical. FIT test is also performed to select the desired pressure in the cementing carefully considered.

کلیدواژه ها:

Wellbore stability ، Private cost function ، Cementing and drilling fluid