..., severe fluid losses, high mud costs, formation damage, and post-well production issues. Clear fluid brine systems such as Calcium Chloride (CaCl 2 ) and Calcium Bromide (CaBr 2 ) are usually preferred because of their compatibility with coals and their ability to minimize formation damage. However...

... wells identified the use of MPD as a possible partial solution to mitigate the usual loss circulation scenario. This document describes the successful implementation of the MPD technique as a supplemental aid for cementing jobs, eliminating cement losses, avoiding formation damage, reducing mud losses...

...: Influx No Influx Acceptable Periodic Acceptable Yes, Continuous What are the goals /expectations of utilization of MPD? Cure Losses – Partial Losses – Severe Losses – Total Losses Reduction in reduced formation damage due to degree of overbalance Avoid...

... or minimizing lost circulation where no drilling time would be lost due to cure losses, also to reduce the formation damage. The C-349 H well was the first UBD horizontal well drilled by AGOCO. The paper discusses the objectives, planning, and the performance of horizontal UBD well as the first well drilled...

... Salimi et.al 5 have studied formation damage in the fracture reservoir formations. They considered a dual porosity model including a warren-Root configuration to simulate the mechanism of productivity improvement by an UBD operation. Description of the problem Xiong and Shan 6 have...

... simulator is used which has features to handle some special models. In this study a new approach is used to model the type of formation damage which is explained earlier. The well is considered to be entirely filled with water as a representative of aqueous drilling fluid. Methodology and Work flow...

... Abstract Underbalanced (UBD) operations are being utilized with increasing frequency as a means of reducing invasive formation damage, minimizing problems with differential sticking, lost circulation, and increasing rates of penetration in many drilling operations. Additional to the operational...

...-wellbore damage. Minimizing formation damage in the near- wellbore region and thus ensuring proper well performance for enhanced productivity of the well also results in increased recovery factor. Formation damage caused by conventional overbalanced drilling (OBD) can be reduced or eliminated through UBD...

... Directional Drilling circulation calender time sabah field conventional drilling problem Drilling zueitina oil company national oil corporation formation damage production rate horizontal well reservoir Introduction This is the first well in Libya drilled with UBD technology. The well...

... conventional drilling techniques, and it has enables formation evaluation while drilling 1 - 5 . It also reduces or eliminates formation damage because there is no fluid lost to the formation in most cases, resulting in higher productivity wells, and possibly increases reserves. 6 - 13 More recent...

... carbonate reservoir complex reservoir mud invasion ubd formation damage capillary force productivity oil rate fractured reservoir invasion ubd operation Introduction Minimizing formation damage that occurs during conventional drilling is a critical point for optimizing an oil field...

... of UBD operations, from which one can easily determine if UBD wells perform better than OBD wells for given reservoir conditions. In this study, we have employed a numerical simulation method that considers formation damage mechanisms like drilling filtration invasion, mud cake, spontaneous...

.../well testing underbalanced drilling reservoir surveillance production monitoring formation damage reservoir characterization correlation productivity iadc spe 81639 equation viscosity production control prob inflow equation Introduction In recent times, however, with increasing...

... damaged rock left open hole would be unproductive. Formation damage from the expected loss of 50,000 barrels of drilling fluid would require a fracture stimulation to regain productivity. To prevent these massive fluid losses while drilling and completing the well, the asset team considered near balance...

... upstream oil & gas drillstem/well testing economics reservoir surveillance mcfd longfellow drilling operation conventionally production control wellbore stimulation caballo mcf month production rate condensate formation damage underbalanced drilling drillstem testing casing...

.... If calibration has already been made and predictions agree with actual measurements there is more confidence in the model and the prediction that the system is underbalanced. Otherwise underbalanced conditions may not be guaranteed, and formation damage could occur. Field data from oil and gas wells are used...

... is based. As mentioned above, sources may include sensors, computer systems, and other data acquisition systems (either manual or automated). Sensors Abstract Formation damage and reservoir attributes can only be effectively evaluated with high quality, pertinent data. Underbalanced operations...

... UBD fluids. These screening procedures assess formation damage potential, account for lost circulation possibilities, and assure wellbore stability. System Design Expert system framework The overall architecture of the expert system is depicted in Figs. 1 through 3 . The expert performs...