Practical Horizontal Cementing Today

Abstract

Horizontal wells present an effective method to maximize production potential and reduce development costs of some oil and gas fields. The ability to predict induced fracture direction with reasonable accuracy can allow the operator to drill in the direction considered most profitable.1 Ideally the well would have extended reach in the proper direction through a stable, fractured formation, would not require stimulation, and would not be subject to the production problems usually encountered in the life of a field. Since horizontal wells are drilled in a variety of formations, operators are experiencing the normal well problems and are finding stimulation and control methods useful for production improvement. This paper will examine problems associated with cementing of horizontal sections and the recent technology advancements that may be applied to help assure a competent annular hydraulic seal. Conventional cemented completions have not been used extensively in horizontal wells since some operators lack confidence in the technology that is available. Problems have been perceived in managing cuttings transport, pipe centralization, effective mud displacement, cement free-water control, and effective placement of a cement seal around the casing. These problems do exist and corrective techniques are complicated by highly deviated wellbores, but technology advances have been made to address horizontal conditions. Proper cementing may continue to provide an economical hydraulic seal for zonal or wellbore segment isolation so necessary to effective stimulation and work-over operations. The use of advanced technology often requires extensive pre-planning and includes the necessity to properly communicate the benefits to field operations personnel to assure the proper implementation of new or different techniques or materials. Little good will come from the best ideas without proper follow-through during application.

Experimental Study of the Use of Tracing Particles for Interface Tracking in Primary Cementing in an Eccentric Hele–Shaw Cell

“…Due to the problematic rheological behaviors of non-Newtonian fluids with and without yield-stress, there are fewer experimental studies about fluid flows in concentric and eccentric annular geometries with similarity to wellbore annulus in primary cementing [4][5][6][7][8][9][10][11][12][13][14][15][16]. In these limited experimental studies, it has been established that the type of flow (laminar, transition, and turbulent) [5,[10][11][12]17,18] and degree of eccentricity affect displacement efficiency significantly [19]. These studies generally stated that turbulent displacement flow is more efficient than the laminar displacement flow [17,18], and the increasing standoff causes a significant effect on the displacement flow of the fluids and cement placement [20][21][22].…”

“…In these limited experimental studies, it has been established that the type of flow (laminar, transition, and turbulent) [5,[10][11][12]17,18] and degree of eccentricity affect displacement efficiency significantly [19]. These studies generally stated that turbulent displacement flow is more efficient than the laminar displacement flow [17,18], and the increasing standoff causes a significant effect on the displacement flow of the fluids and cement placement [20][21][22]. In cases like washout sections, the effect of inner pipe eccentricity is not significant for displacement in the washout section [23].…”

“…By using large-scale eccentric annular geometry, the importance of the rheological properties of the realistic non-Newtonian fluids for fluid flow and hole cleaning performance was expressed extensively [14][15][16], and the propagation of the fluid interfaces and displacement efficiency were characterized [24]. It was indicated that an enlarged irregular section, i.e., a washout causes an improvement in displacement in some scenarios in strongly inclined wellbores [17]; while being independent of the displacement efficiency in the washout itself, the presence of washouts may lead to poorer cement quality downstream of the washouts [23].…”