Modeling of Filter Cake Composition in Maximum Reservoir Contact and Extended Reach Horizontal Wells in Sandstone Reservoirs

Abstract

Drilling mud should be properly designed to build an effective filter cake on the formation face during the drilling process. This filter cake should be removable to allow the oil and gas production. The need for removal increases when the liftoff pressure is high or when the formation drawdown is extremely low. An effective filter cake removal design includes the knowledge of the filter cake composition along the horizontal section. This paper, for the first time, introduces material balance model to predict the composition of the filter cake along the length of the lateral of an actual horizontal well drilled in a sandstone formation. The model is based on the material balance of two sources of solids: the first one is the drilling fluid solids and the second one is the drilled-formation solids. The mud used to drill the rock was contaminated by the drilled-formation solids. The parameters used to construct the model were composition of the mud and formation, efficiency of each separation stage, rate of penetration (ROP), and mud circulation rate. The model was validated with actual mud samples collected from different locations along the horizontal section of a sandstone formation. The model showed that the sand content in the filter cake is affected by ROP, rock composition, mud composition and volume, and efficiency of sand separation equipment. We came up with several correlations that can be used to design the drilling fluid operations in horizontal well to avoid the formation of irremovable filter cake.

Effect of Arenite, Calcareous, Argillaceous, and Ferruginous Sandstone Cuttings on Filter Cake and Drilling Fluid Properties in Horizontal Wells

“…The cuttings generated with the different core samples were mixed with the drilling fluid with concentrations of 15% and 30 wt.%. This range of the cutting content was observed as the maximum amount of sand content that may contaminate the drilling fluid while drilling long horizontal sections [12,23]. The effect of different sandstone cutting content (quartz arenite, calcareous, argillaceous, and ferruginous) on drilling fluid density was not significant.…”

“…On the other hand, the formation permeability and lithology play a great role on the cumulative mud filtrate loss [10,11]. Thus, the filter cake buildup through either static or dynamic conditions was simulated to understand the filter cake properties [12][13][14][15].…”

Complex barite filter cake removal using in-situ generated acids by thermochemicals

“…In general, the filter cake layer is classified according to the source of the solids formed in the cake layer. It is mainly, either the drilling fluid solid additives (weighting material of the drilling fluid such as shown in Table 1) or the formation solids (cuttings) accumulated with the drilling material during the drilling operations, if they are not completely removed 21,28,29,[34][35][36] . The filter cake solid particles are usually covered by the polymer coat and/or starch that restricts the reaction of the filter cake solids with the solvents 13,15,37 .…”

“…Thus, several studies were focused on evaluating the factors affecting the reservoir quality in sandstone formations before exploration, and during and after the drilling operation 14,21,24,25 . Due to the heterogeneity of sandstone reservoirs and the presence of clay minerals 21,26,27 , extensive research focus has been performed on the effect of the sand content on the drilling fluid and filter cake properties 14,28,29 . The study 28 reported that the filter cake may form with a quartz content of up to 20% and in some portions may reach up to 40%.…”

“…Due to the heterogeneity of sandstone reservoirs and the presence of clay minerals 21,26,27 , extensive research focus has been performed on the effect of the sand content on the drilling fluid and filter cake properties 14,28,29 . The study 28 reported that the filter cake may form with a quartz content of up to 20% and in some portions may reach up to 40%. These filter cakes may not be susceptible to any of the abovementioned removal processes.…”