The use of simulation software applicable to the various stages of petroleum engineering allows for maximizing decision-making and, in parallel, minimizing possible failures, problems, and incidents during each intervention. Furthermore, a computer tool provides the user with instant and accurate results that can be used during personnel training and education. Several researchers have studied the effective displacement of drilling fluid by cement slurry and the mixing of the two fluids during primary cementing operations [1-3]. The first 2D annular displacement simulator was introduced in 1990; however, the industry has kept its attention on the issue of mud displacement for the last 60 years [4].

Various studies have described the importance of cementing, software development, automation, and several operations in the petroleum industry. Among these, primary cementing is the most important task performed during well completion. This involves depositing a specific amount of cement slurry in the space between the drilled formations and the casing pipes installed inside the well [5]. The primary purpose of this operation is to provide zonal isolation, improve wellbore stability, seal off oil and gas in the formation, and prevent uncontrolled flows that could occur at the wellhead [6-8]. To ensure the integrity of oil wells, it is essential to avoid problems during primary cementing and before any additional thermal, mechanical, and/or chemical loads are applied [9]. Significant losses of mud or slurry into the formation can have a negative impact on the petroleum industry, the economy, the integrity, and the life cycle of the well [10]. It is essential to carry out primary cementing activities with profound knowledge of the actual behavior of the fluids in the wellbore. Otherwise, a possible change in the turbulent flow profile might occur, reducing the isolation between the edge of the formation and the pipes [11]. The efficiency of the displacement process is influenced by several factors, including the condition of the well, the formulation and properties of the drilling fluid and cement (including the spacer and flushing fluid), and the flow regime during displacement, among others [12, 13]. If the pipes were corroded or damaged, it could lead to contamination of the hydrocarbon flowing to the surface or it could be conducted to an area of lower pressure. Cementing aims to protect the outer walls of the pipes against blows during the drilling process and to create a seal between the areas of lost circulation. Hence, primary cementing is vital during wellbore completion.

The importance of a primary cementing system for personal computers as support for the soundness of cementing jobs has been identified by [14]. They also justified the development of this system by pointing out that it saves operation time and simplifies decision-making. However, Villegas-Javier later identified that the development and execution of integral cementing in wells with severe conditions, such as reduced annular spaces and depressed zones, are current technical challenges in the Mexican petroleum industry [15], while [16] consider that investigating displacement efficiency is crucial for improving the quality of cementing. Visual Basic is one of the most used programming languages in engineering, as it is frequently used for simulator development in the petroleum industry. According to [17], engineers can develop various applications using Visual Basic, which is an easy-to-learn and flexible programming tool that can be tailored to their needs. For instance, an interactive pipe selection and laying software with commonly used engineering physical units was developed using Visual Basic [18]. Additionally, [19] mentions that the Shell "SPOT" software has its origins in Microsoft Excel's Visual Basic, while Utsalo et al. [20] created a Microsoft Excel Visual Basic application for casing selection.

Primary cementing involves complex calculations and considerations, which can be overwhelming even with the availability of sufficient information, tools, physical and chemical characteristics of additives, and laboratory equipment for slurry design. The purpose of this work is to develop an open-source computational tool with a graphical, numerical, and schematic interface to simplify the teaching and learning of primary cementing-related operations.

The software was developed by following the steps outlined below: i) Firstly, a wellbore diagram is created, which includes the wellbore, casing, and liner as per the oil well design. ii) The relationship between the volumetric equations for annular, internal, and total volume is established based on the geometric design of the well. iii) The following factors are then integrated to develop the software: wellbore volumetry, slurry design, percentage of each slurry additive, operating characteristics of the mud pumps (liner diameter, rod diameter, and length, volumetric efficiency), volume of displacement fluids, rheology, and others. iv) Finally, a wellbore diagram is created that includes drilling, displacement, and slurry fluids, as per each cementing stage. The CEMPRI software is developed using the methodology described in the specialized literature for the training of engineering and operational technical personnel in the field of drilling and well maintenance [21]. This is shown in the flow diagram in Fig. 1.

Figure 1 Source: Own elaboration.

The CEMPRI software was written in Visual Basic for Applications in Microsoft Excel. One of the advantages of this application is its simple and intuitive design with a comfortable and user-friendly interface. Additionally, The CEMPRI software provides clear and concise graphical data visualization.

Fig. 2 shows the main cover of the CEMPRI software named: “Datos del Pozo/Well Data”, requesting the following information: name, number, location, placement, and classification of the well. Additionally, the name of the engineer or technician responsible for designing the well is also required.

Figure 2 Source: CEMPRI software.

An illustrative example was chosen to demonstrate the capabilities of the CEMPRI software, consisting of three parts. Table 1 provides the input data for wellbore diagram schematization. Table 2 contains the information to carry out the design and calculations of each stage to generate the diagram. The cementing space can be designed for one or two intervals, the slurry density, cement type, and the type and percentage of additives can differ between these intervals.

Table 1

Source: Own elaboration.

Table 2

* Quantities determined in Laboratory data as described in Figure 6.

The exercise example results obtained for each stage in the primary cementing are presented in Table 3. Fig. 8 comprises six images, which outline the wellbore diagram of each stage according to its design considerations and characteristics. For each of the five stages, the specific design characteristics are considered while generating the two graphs shown in Fig. 8: "Density & Time" and "Accumulated Flow Rate & Time." The wellbore diagram for the sample well is depicted in Figure 8a. The diagram shows the annular spaces (slurry volume) for each stage in five colored rectangles: yellow, green, blue, purple, and orange. The wellbore diagram is composed of four casing pipes and a liner. For Figures 8(b-f), the yellow color represents the drilling fluid volume, while the red, green, and purple colors correspond to the displacement fluids before and after the slurry volume. The dark green and gray colors represent lead and tail slurry volumes, respectively.

Table 3

Source: Own elaboration.

Figure 8 Source: CEMPRI Software.

Fig. 8b corresponds to the first stage, where the volume of slurry (represented by dark green and grey lines) and the displacement fluids (shown in red, green, and purple) constitute 91.3% of the internal capacity of the pip. The remaining 8.7% is occupied by the drilling fluid (in yellow) and is present in the annular space. The second stage is represented by Figure 8c, where the total slurry volume was divided into two equal portions referred to as “lead” and “tail”. Here, the total volume of displacement fluids (in red, green, and purple) and slurry (dark green and gray) occupy 99.2% of the internal capacity of the pipe while the remaining 0.8% is occupied by the drilling fluid (yellow). It is important to note that in this case, “Lead” Vslurry is equal to “Tail” Vslurry.

The third stage is represented by Figure 8d. At this stage, the slurry volume and displacement fluids together occupy 46.3% of the internal capacity of the pipe, while the drilling fluid occupies the remaining 53.7%. In this case, we consider “Lead” Vslurry < “Tail” Vslurry.

Figure 8e represents the fourth stage, in which 38.9% of the internal pipe capacity is occupied by the total volume of mud and displacement fluids, while the remaining 61.1% is occupied by drilling fluid. In this case "Lead" Vslurry > "Tail" Vslurry.

The fifth stage corresponds to Figure 8f, where a cemented casing (liner) is observed. This pipe is anchored at a shallower depth than the last pipe, depending on the overlap length between the last pipe and the liner.

It is important to note that the physical unit of the additives that make up the slurry is the percentage symbol (%) [34]. Chaudhry [35] presents a diagram of the pipe and wellbore for each stage of the process but does not include a wellbore diagram or graphs showing the pumping and distribution of different types and volumes of fluids used for primary cementing.

The CEMPRI program was created using Visual Basic for Applications in Microsoft Excel, with a macro environment. It is an efficient and useful software for instantaneously calculating primary cementing. The interface design is simple, intuitive, and easy to use, with fast communication and adaptation between the user and the program. It is a versatile tool that integrates a wellbore diagram for up to five stages, allowing for both numerical and graphical calculations individually, with a maximum depth of 5,000 m.

The CEMPRI software was developed to integrate theoretical knowledge with practical activities in oil well design and field departments. The program includes wellbore schematization, diagrams, and graphics that follow the real values of the bits, casing pipes, cementing intervals, chemical materials in the slurry design, pump operating characteristics, volumes, depths, hydrostatic pressures, total hydrostatic pressure, circulation equivalent density, and much more. It is important to have prior knowledge of all these parameters and variables when conducting calculations, analyses, and interpretations. CEMPRI is an open-access academic tool that aims to become a leading program in the field.