Engineered Fiber Based Lost Circulation Pill to Abridge Lost Circulation of Geothermal Well

Loss circulation is a major problem and known as the biggest challenge during drilling and well construction.This can leadsto various consequences,such as stuck pipe, loss of material and time to combat the losses, and even losing the well itself. Severe loss circulation conditions are often met while drilling geothermal wells in Indonesia. Partial to total losses have start experienced since drilling the surface section. Cement plugs is one of the conventional methods to cure losses. Number of cement plugs differ from one well to another well. Even in some wells, number of cement plugs performed for loss circulation plug can be over 30 times with total of more than 4,000 barrels of cement slurry pumped. Solution other than basic loss circulation material and cement plug must be developed to optimize curing loss time. Engineered fiber base concentration which is include; Base Fluid, LCM and Solid Package was obtained from simulation, then trial and error in laboratory was conducted. Based on the final recipe, the control pill was able to hold pressure and not leaking, even when using 5 mm grid clearance. Additional combined stiff fiber and flexible fiber with concentration of 6 lbs/bbl sufficient to hold exessive loss circulation

Impact of Wet Supercritical CO2 Injection on Fly Ash Geopolymer Cement Under Elevated Temperatures for Well Cement Application

An alternative cement system created through geopolymerization of fly ash offers favorable properties such as able to resist acidic fluids and possess high compressive strength. However, the application of fly ash geopolymer as wellbore cement under carbon dioxide (CO2) environment at elevated temperature is not well recorded in the literature. This paper character- izes the fly ash-based geopolymer cement and experimentally investigates its mechanical and microstructure changes after exposed to CO2 under elevated temperature. Microstructure identification on the altered cement paste was conducted by the analysis of XRD and SEM. In this study, fly ash-based alkali-activated cement was made using 8 molal sodium hydroxide and sodium silicate as alkali activators. The results found that crystal-like shape identified as calcium carbonate was formed at the surface of spherical fly ash particle after carbonation formation. The strength of geopolymer cement was found not to be decreased although carbonation process was occurred. Microstructure analysis revealed that zeolite was formed during CO2 acid exposure for geopolymer cement which contributes to the strength development

Integrated Reservoir Study to Optimize Gas Production of Water Drive Gas Reservoir Case Study: Lower Menggala Gas Field

Production optimization in mature field water drive gas reservoir is not easy especially when water already breakthrough in producing wells. An integrated reservoir study is needed to get reliable strategy to optimize production of water drive gas reservoir.   This research presents the integrated reservoir study of Lower Menggala (LM) Gas Field which is located Central Sumatera Basin, Riau Province. LM had been produced since 1997, current RF are 55%, which is quite high for water drive gas reservoir. The current gas rate production is about 1.97 MMscfd with high water production around 4250 BWPD, consequently some of wells suffered liquid loading problem   This research comprises of well performance analysis, estimate OGIP, aquifer strength of the reservoir by using conventional material balance method and modern production analysis method then conduct dynamic reservoir simulation to identify the best strategy to optimize gas production. Economic analysis also be performed to guide in making decision which scenario will be selected. DST analysis on DC-01 well defined reservoir parameter, boundary and deliverability which are P*= 2520 psia, k= 229 mD, Total skin= 8, detected sealing fault with distance 175 m, and AOF 45 MMscfd. Conventional material balance method gave OGIP 22.7 BScf, aquifer strength 34 B/D/Psi, whereas modern production analysis estimated OGIP 22.35 BScf, aquifer strength 34 B/D/psi. Those two method shows  good consistency with OGIP  volumetric calculation with discrepancy OGIP value +/- 1%. Six (6) scenario of production optimization has been analyzed, the result shows that work over in two wells and drilling of  1 infill well (case 6) achieve gas recovery factor up to 75.2%, minimal water production and attractive economic resul