How to Control Sand Production Using Geo-Mechanics Methods
Optimized Production with Reduced Risk for Sand Production
Measurement is crucial for the evaluation of any sand management system. In the context of oil and gas well, the production of sand proves to be a problem to the operator during execution of the processes and procedures. This is because sand and the relevant particles in other cases contribute towards low productivity and a normal cutback in the production system, in the range of 20 to 75 percent within the essence of oil and gas wells. It is difficult to ignore the concept of produced sand. This makes it critical for the well producing in relation to sandstone to have an effective and efficient sand monitoring system. The sand management system should either be online or instant/real-time reading. Operators can save millions of financial resources through adoption and implementation of non-invasive sand monitoring equipment. The need and objective to increase the level of production per well and increased expenses in relation to subsea makes it vital to adopt and apply subsea-monitoring system (Haugsdal, 2007).
Operating range concept refers to the physical knowledge behind the adoption and implementation of sand management systems. This is because the sandstone reservoir must possess the theoretical window essential for the operation of the sand management system. Another crucial aspect of sand production is the element of transport. The worst scenario occurs in case of production of sand under minimal velocity insufficient in the lifting of the sand out of the well. This scenario will lead to the eventual collapse of the well. Sand management refers to the process of controlling the production of sand, enhancing the integrity of installation, and ensuring well performance of the well reservoir. Sand management realizes rapid growth and development because of adoption of accurate detectors thus management in a safe and sufficient way. In the management of sand detectors, there have been numerous ClampOn sand detectors to aid the process (Haugsdal, 2007).
Typical Sand Production Problems: Case Studies and Strategies for Sand Control
There are five crucial problems in relation to the production of sand: unconsolidated formations, reservoir pressure resulting into depletion, high flow rates (sudden in nature), and water break-through for weak formations, and high lateral tectonic forces (Morita & Boyd, 1991). It is crucial to minimize the essence of these problems through the management of sand production. Several strategies are applicable towards the management of sand production. During the production of sand, two crucial failures occur: tensile and shear failures. Tensile failure problems during the production of sand occur when the flow rate is relatively low.
The dominance of the shear failure problem in relation to sand production occurs when there a decrease in the bottom-hole pressure. The tensile failure is affected by the loss of capillary pressure that operates towards the reduction of the cohesion of the sand grains. In the development of the procedure for the evaluation of strength, there are two proposals (Morita & Boyd, 1991). The first proposal entails full analysis: plug sample, core preparation, triaxial test, hardness measurement, and other relevant data crucial for the execution of the analysis. For the full analysis, it is ideal to ± 300 psi in relation to the measurement of the pressure of the well. The ration of the diameter must be greater than 2. For example, 1″0 x 2″L, 1.5″0 x 3″L. This applies to the analysis of the plug sample. The second proposal focuses on the simplified evaluation in relation to the analysis of the low budget. In the advancement of technical knowledge, there has been update on the perforation cavity stability thus the eventual reconsideration of the post failure theory. This aims at ensuring that the model is consistent with the field observations. Most of the sand production problems result form expansion of the shear zone with reference to the perforation cavities. This makes it critical to adopt one of these two mechanisms to eliminate or minimize the essence of sand problems during production. The first strategy involves elimination of the weak intervals from the perforation design. The second mechanism involves lowering the drawdown with the aim of preventing sand problems during the production (Morita & Boyd, 1991).
Minimize Sand Production by Controlling Wellbore Geometry and Flow Rate
In the prevention of the sand problems, it is first necessary to understand the essence of the challenges within the production of sand. Sand production emanates from the transformation of strength in relation to the formation of rocks in the process of drilling, perforation, and operations during production and the relevant forces. In the prevention of sand production problems, it is ideal to adopt and implement the wellbore geometry mechanisms. Wellbore geometry mechanisms has great influence on the flow rate of the sand thus the ability to minimize the sand production problems while enhancing or optimizing the production process within the field. This process entails crucial evaluation of the sand production process through application of static and dynamic tests.
The static and dynamic tests or evaluation of the sand production process is executed within the model of the wellbore geometry reflecting on the unique angles, perforation shot density, pattern, and flow rate (Samsuri et al, 2000). The examination of flow rate in relation to this model adopts and implements Servo Control Compression Testing Machine (SCCTM). The results of effective and efficient application of the wellbore geometry model indicate rapid reduction on the oil production. In the same context, there is an increase in the volume or level of sand production. The production of sand is dominated by the influence of the breakage around the cementing materials thus the essence of production of large particles of sand. The model has the ability to increase the production of sand after the attainment of the stress level of about 35 to 60 percent with reference to compressive strength of the rock. This is usually followed by extensive reduction in the recovery of oil to about 55 to 73 percent (Samsuri et al, 2000). The increase in the production of sand is associated with increases in the flow rate, angle, and shot density.
This also occurs under effective transformation of the perforation patterns ranging from spiral, in plane, and eventually inline. This is usually effective for the wellbore geometry models that have angles of less than 10 degrees. This is an indication that the reduction of sand production problems depends on the minimization of the angle, flow rate, and shot density through variations of perforation patterns (Samsuri et al, 2000). “After one year of implementation and production, the oil rate is 62 BOPD and water production is 2483 BWPD”. This is reflection on the reduction of sand production following effective control of the well geometry.
Identifying the Formation failure Mechanism and Controlling Sand production from the Upper Tuscaloosa Formation in the East Heidelberg Field Mississippi
It is crucial to identify the problems of sand production before attempts towards their elimination. It is evident following the completion of the wells in the upper Tuscaloosa and the vast of Christmas Green formations have experienced the problem of producing formation sand in relation to their productive lives (Brent Taylor et al, 2003). In the process of executing the first aspect of the prevention of sand production problems (identification or detection of the problems), there is an effective and efficient systematic process aiming to elaborate or illustrates the failure in relation to the mechanisms of production or development.
The systematic problems were able to contribute towards the elimination and controlling the production of sand with minimal restrictions on the fluid deliverability in the context of the four wells within the region. This adds to the ability of the system in accurately identifying the failures or problems within the production mechanisms (Brent Taylor et al, 2003). There are different mechanisms adopted with the aim of reducing the failure or solving the sand production problems. The first mechanism is the provision of a complete work over to the wells in order to deal with the problem of the plugging of the gravel-pack. This mechanism will act towards the reduction of sand production. The other mechanism for eliminating the problems is through extensive designing of the well. In case of problems emanating from the completion of well, it is crucial to recomplete the well reservoir. Another aspect in the minimization of sand production is the adoption and implementation of the hydraulic stimulation in the presence of a surface modifying agent. This is through extensive control of the migration fines as in the case of Upper Tuscaloosa formation. The strength of this model or methodology depends on effective and efficient application of internal gravel-packing mechanisms that have the ability to retain the hydraulic stimulation within the fractures thus controlling the production of sand (Brent Taylor et al, 2003).
Solving Completion options for Underground Gas Storage through Geo-mechanics
The main determinate or force that results into the need for gas storage within the production is constant variation on the demand of the gas on a weekly, monthly, and yearly contexts. There is a need to store the gas within the consumption points with the aim of meeting the fluctuations in demand through effective supply method and mechanisms (Subbiah et al, 2008). This is an indication that the operators of the underground gas production need to optimize the storage of the resource through minimization of the cost of its storage within the consumption points. In addition, it is ideal to ensure safety in the process of injection and production cycles. This is because the process of storage of the gas is associated with changes in pressure.
There is also the increase in relation to the stress rate acting on the reservoir rocks. Changes in stress result from two events: variation in the reservoir pressure and injection or production rates (Subbiah et al, 2008). These changes may be insufficient in aiding the role of the rock thus the development of the sand production problem. Sand production is critical in that it has the ability to demolish or destroy/damage the wellbore or surface equipment thus rendering the storage of gas as unviable. It is, therefore, vital for the operators to understand the concepts and states of the stress levels created in the process of storing the gas at the consumption points. This is relevant towards the minimization of sand production in affecting the essence of gas storage and its viability. It calls for the adoption of geo-mechanical review of the potential sand production towards its elimination from the storage concept. One of the eminent models for the elimination of sand production is known as the geo-mechanical model. This relates to the description of the details of the construction of the well with the aim of understanding and limiting the problem of sand production. The basic of this model is to integrate all valuable data in relation to earth strength, stress, and pressure (Subbiah et al, 2008).
References
Subbiah et al, (2008).
Solving Completion options for Underground Gas Storage through Geo- mechanics,
SPE 116409.
Brent Taylor et al, (2003). Identifying the Formation failure Mechanism and Controlling Sand production from the Upper Tuscaloosa Formation in the East Heidelberg Field Mississippi, SPE 84498.
Samsuri et al, (2000). Minimize Sand Production by Controlling Wellbore Geometry and Flow Rate, SPE64759.
Morita N. & P.A. Boyd. (1991). Typical Sand Production Problems: Case Studies and Strategies for Sand Control, SPE 22739.
Haugsdal Torbjoern. (2007). Optimized Production with Reduced Risk for Sand Production.
