What is the effect of sand production in well production? (1Mark) Give two of the controllable and two of the uncontrollable issues of wellbore instability. (2Mar List sand control methods mentioned in the paper. (2 Marks) Sand production control mechanisms during oil well production and construction Arman Salahi ", Ali Naghi Dehghan b,**, Seyed Jamal Sheikhzakariaee ", Afshin Davarpanah d. eDepurment of Manhematich, Meryamyth thicersio. Aberownyth 523382 , UK A. R.T.CLE INFO A. B S.T.R A C.T Artiche histocy: Sand production is considered as one of the signifcant production issues that significantly reduce Hleceived 30 fantiary 2021 wellbore prodactivity. The process of sand or solids production in production operations is one of the lleceived in revised form 23 febcuaty 2021 crucial operational inefficiencies that can lead to welis collapsing, Besides, the drilling mud might erupt Anogptrd 25 Feliruary 2021 through the formation. Therefoce, it is essential to properly determine what types of solids or sand are Available onitine 3 March 2021 produced to correctly predict efficient sand control mechanisms. This paper aimed to compare different sand production control mechanisms and how to control or minimize sand groduction. Moreover, we 1. Introduction Ardestanj er al.4 2019; Aroyehun et al.4 2018; Bowes and Procter 1997; Davarpanah and Mirshekari 2019ts: McLeilan 1996; Wellbore instabitity is considered to sotne known and unknown Mohiuddin ef al., 2001), Determination of sand types would help factors, which might affect the production operations (Bere and production operations as some of the sands might be useful in the Kato, 2019: Chen et al. 2020: Cohen et al. 2019, Davarpanah and pore space cleaning. Typically, solids with an average size of 50-75 Mirshekari, 2019a, Dehghani, 2016; Garolera et al, 2019; Gholami can provide a bearing solids load that shoald be controlled et al. 2016). It is classified as controllable and uncontrollable is- (Davarpanah et al. 2019: Davarpanah and Mirshekati, 2018: 2hu sues (Davarpamath, 2020; Hu et al., 2020; Junmano et al., 2016; et al. 2020). The mechanism of sand production control is generFakhimzhanova et at. 2020: Salehi et al., 2019). The former clas- ally dragged force reduction and formation-strength increase (Afsification is consisted of transient pore pressure, well irclination. Awad and Desoulky 1997: Al-Awad and Al-Misned 1997; erosion, and fluid-rock interaction (Davarpanab ef al 2018: Davarpanah and Natsabeh 2017: Dolui etal, 2016). Rahman et al. Rabtani et al. 2018; Song et al. 2020; Speight. 2020: Sun et al. (2010) developed a decision-making flowchart to implemert 2020;- Tovar, 2018: Wangi and Stiarma, 2019; Yan et al. 2018), different criteria to select sand production control mechanisms. However, the second classification has nainly consisted of tectonic. This is based on the passive sand production control and integrated stresses, unconsolidated formations, natural faults and fractures, geomechanical approaches. It is schematically shown in Fig. 1 mobile formations, and higher in-situ stresses (Asthashah) (Rahman et al. 2010) with the fluid during the production and extraction of sand oil. In different amounts of moisture (10\%, 15\%, and 20\%) were performed. this part of the study, different sand control methods and numerical According to Fig. 5 , the sand production rate is generally reduced by solutions were discussed and compared. increasing the amount of moisture. According to research by Papamichos et al. (2001), sand production rates are related to the 3.1. Injection pressure impact non-adhesion or adhesion of sand grains around the wellbores. As Operational factors are the strategies used to produce oil and - the saturation increases, the intermolecular uptake between the gas, such as pressure difference, injection pressure, flow rate, and grains of sand increases due to capillaries. It may lead to an increase production rate. To investigate the effect of injection pressure on in the sand mass's adhesion and thus a decrease in the rate of sand sand production, a series of tests were done on dry sands (zero production with increasing moisture. Therefore, according to Fig. 5, humidity) with injection pressure variables of 150200KPa were the sand production rate is significantly reduced by increasing the performed. The results of these tests are shown in Fig. 4. As can be 2001 : Wiggs et al., 2004). jection Fig. 4, sand production increases with the increase of in- _. Many researchers have studied all sand control methods. According to the observed results, when the well is closed several forces affect sand arcs' stability in critical situations, which has times to make the requirements for testing or high series operaincreased by injection pressure rise (Yim 1994). According to the tions performed, the sand production rate increases. The mecharesearch of Clearley et al. (1979), the first layers of each formation nism that leads to an increase in sand production requires further have failed due to their dependency on the adhesive forces. investigation. The sample used is a relatively soft rock, measured Moreover, the characteristics of bridging and the redistribution of with a single-axis compressive strength of 24.5 MPa and an estistress created by sand arcs are other crucial parameters. Therefore, mated apparent adhesion resistance of 7.4 Mpa. The proportions of the rate of sand production increases continuously by injection the sand volume produced in the initial production cycle when pressure rise according to the theory of Clearley et al. (1979) and using water with 3.5% salt are used for the fluid pressure of 2,1.25, Yim et al. (1994). and 0.5MPa are 3.8%,1.7%, and 0.5%, respectively. Higher amounts of sand are produced at high permeability fluid pressures due to the 3.2. Sand moisture reduced pressure around the wellbore (Godinez-Brizuela and Niasar 2020; Zheng et al. 2020). To investigate the effect of moisture on sand production, some The formation of soft grains has been widely discussed in the laboratory tests with an injection pressure of 180150kPa with literatre by previous researchers. Zeitsu (1985) provided a 364